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Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) [email protected]. nospam edu Center for Cosmology and AstroParticle Physics The Ohio State University 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology (SNOWPAC)

2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) [email protected]

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Page 1: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Dark Matter Searches with IceCube

Carsten

Rott(for the IceCube

Collaboration)carottmpsohio-state nospam edu

Center for Cosmology and AstroParticle

PhysicsThe Ohio State University

2010 Snowbird Workshop on Particle Astrophysics Astronomy amp Cosmology (SNOWPAC)

Presenter
Presentation Notes
13

Overview

Motivation

The IceCube

Neutrino Telescope

Probing for Dark Matter

WIMP-Nucleon Scattering cross section

Sun

Self-annihilation cross section

Galactic Halo and Center

Future Outlook and DeepCore

Conclusions

Carsten

Rott

2

SnowPAC

March 23-28 2010

IceCube

Lab IceTop80 stations each with 2 Cherenkov

detector tanks

InIce

Array86 strings with 60 DOMsCurrently 79 strings deployed 59 string taking data Transition to 79 string detector configuration in April

Deep Core Extension for 10-100GeV neutrino detection

Motivation

Carsten

Rott

3

SnowPAC

March 23-28 2010

Overwhelming Observational Evidence

Dark Matter already gravitationally ldquoobservedrdquo but hellip

What is it

What are itrsquos properties

1E 0657-56 -

Bullet Cluster

D Clowe et al astro- ph0608407 AJ 648 (2006) L109- 113

Coma Cluster

Carsten

Rott

4

SnowPAC

March 23-28 2010

Presenter
Presentation Notes
Bullet cluster13Weak lensing rArr Mass not centered on gas13 rArr Confirmation of existence of Dark Matter1313At the same time he applied the virial theorem to the Coma cluster of galaxies and obtained evidence of unseen mass thus starting off the debate on what is now called dark matter 13the virial theorem provides a general equation relating the average over time of the total kinetic energy of a stable system consisting of N particles bound by potential forces with that of the total potential energy where angle brackets represent the average over time of the enclosed quantity Mathematically the theorem stateswhere Fk represents the force on the kth particle which is located at position rk1313The Coma Cluster (Abell 1656) is a large cluster of galaxies that contains over 1000 identified galaxies131933 Zwicky estimated mass of the coma cluster

Dark Matter Understanding

Observational Evidence

Non‐baryonic

Cold massive

Not strongly interacting

Neutral

Stable (or long lived)

WIMP ‐

Particle Nature

Mass

Cross sections

Self annihilation ltA

vgt

Interaction with matter

WIM

P

Measure

X

Carsten

Rott

5

SnowPAC

March 23-28 2010

A Weakly Interacting Massive Particle (WIMP) is generic Dark Matter particle candidate that ldquofitsrdquo

the Dark Matter picture

WIMPs

are prominent Dark Matter candidates

Arise naturally in various well-motivated theories (SUSY Extra Dimensions hellip)

Produced naturally with the correct thermal relic density ldquoWIMP miraclerdquo

Predict signals that might be observable in current and near future experiments

Presenter
Presentation Notes
The recipe for a WIMP is simple just introduce an extension of the SM with13A new stable massive particle that couples to SM particles but with zero electric and color charge and not strongly coupled to Z boson (otherwise excluded by direct detection)

Present abundance

Equilibrium abundance

[Jungman Kamionkowski Griest 1996]

Ways to Study WIMPs

q

q

Carsten

Rott

6

SnowPAC

March 23-28 2010

Thermal relic

Indirect Detection

Nuclear Recoils

ProductionProduction

arXiv0912

3592

WZb em p D

˜

˜

Scattering

Annihilation

Thermal Relic

W Zb e pD

Presenter
Presentation Notes
CDM particles as thermal relic Non relativistic at freeze-out relic density is set by the pair annihilation rate into lighter SM particles13Production of Dark Matter particle in the early universe13All decay except stable particles (LSP for example in SUSY for R-parity conserving scenarios)13Equilibrium density is given by N_eq1313As the universe expanded the temperature of the plasma became smaller than the WIMP mass While annihilation and production reactions remained in equilibrium the number of WIMPs produced decreased exponentially as e1048576m=T (the Boltzmann factor) since only particle-antiparticle collisions with kinetic energy in the tail of the Boltzmann distribution had enough energy to produce WIMP pairs

Indirect Detection with Neutrinos

Carsten

Rott

7

SnowPAC

March 23-28 2010

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 2: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Overview

Motivation

The IceCube

Neutrino Telescope

Probing for Dark Matter

WIMP-Nucleon Scattering cross section

Sun

Self-annihilation cross section

Galactic Halo and Center

Future Outlook and DeepCore

Conclusions

Carsten

Rott

2

SnowPAC

March 23-28 2010

IceCube

Lab IceTop80 stations each with 2 Cherenkov

detector tanks

InIce

Array86 strings with 60 DOMsCurrently 79 strings deployed 59 string taking data Transition to 79 string detector configuration in April

Deep Core Extension for 10-100GeV neutrino detection

Motivation

Carsten

Rott

3

SnowPAC

March 23-28 2010

Overwhelming Observational Evidence

Dark Matter already gravitationally ldquoobservedrdquo but hellip

What is it

What are itrsquos properties

1E 0657-56 -

Bullet Cluster

D Clowe et al astro- ph0608407 AJ 648 (2006) L109- 113

Coma Cluster

Carsten

Rott

4

SnowPAC

March 23-28 2010

Presenter
Presentation Notes
Bullet cluster13Weak lensing rArr Mass not centered on gas13 rArr Confirmation of existence of Dark Matter1313At the same time he applied the virial theorem to the Coma cluster of galaxies and obtained evidence of unseen mass thus starting off the debate on what is now called dark matter 13the virial theorem provides a general equation relating the average over time of the total kinetic energy of a stable system consisting of N particles bound by potential forces with that of the total potential energy where angle brackets represent the average over time of the enclosed quantity Mathematically the theorem stateswhere Fk represents the force on the kth particle which is located at position rk1313The Coma Cluster (Abell 1656) is a large cluster of galaxies that contains over 1000 identified galaxies131933 Zwicky estimated mass of the coma cluster

Dark Matter Understanding

Observational Evidence

Non‐baryonic

Cold massive

Not strongly interacting

Neutral

Stable (or long lived)

WIMP ‐

Particle Nature

Mass

Cross sections

Self annihilation ltA

vgt

Interaction with matter

WIM

P

Measure

X

Carsten

Rott

5

SnowPAC

March 23-28 2010

A Weakly Interacting Massive Particle (WIMP) is generic Dark Matter particle candidate that ldquofitsrdquo

the Dark Matter picture

WIMPs

are prominent Dark Matter candidates

Arise naturally in various well-motivated theories (SUSY Extra Dimensions hellip)

Produced naturally with the correct thermal relic density ldquoWIMP miraclerdquo

Predict signals that might be observable in current and near future experiments

Presenter
Presentation Notes
The recipe for a WIMP is simple just introduce an extension of the SM with13A new stable massive particle that couples to SM particles but with zero electric and color charge and not strongly coupled to Z boson (otherwise excluded by direct detection)

Present abundance

Equilibrium abundance

[Jungman Kamionkowski Griest 1996]

Ways to Study WIMPs

q

q

Carsten

Rott

6

SnowPAC

March 23-28 2010

Thermal relic

Indirect Detection

Nuclear Recoils

ProductionProduction

arXiv0912

3592

WZb em p D

˜

˜

Scattering

Annihilation

Thermal Relic

W Zb e pD

Presenter
Presentation Notes
CDM particles as thermal relic Non relativistic at freeze-out relic density is set by the pair annihilation rate into lighter SM particles13Production of Dark Matter particle in the early universe13All decay except stable particles (LSP for example in SUSY for R-parity conserving scenarios)13Equilibrium density is given by N_eq1313As the universe expanded the temperature of the plasma became smaller than the WIMP mass While annihilation and production reactions remained in equilibrium the number of WIMPs produced decreased exponentially as e1048576m=T (the Boltzmann factor) since only particle-antiparticle collisions with kinetic energy in the tail of the Boltzmann distribution had enough energy to produce WIMP pairs

Indirect Detection with Neutrinos

Carsten

Rott

7

SnowPAC

March 23-28 2010

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 3: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Motivation

Carsten

Rott

3

SnowPAC

March 23-28 2010

Overwhelming Observational Evidence

Dark Matter already gravitationally ldquoobservedrdquo but hellip

What is it

What are itrsquos properties

1E 0657-56 -

Bullet Cluster

D Clowe et al astro- ph0608407 AJ 648 (2006) L109- 113

Coma Cluster

Carsten

Rott

4

SnowPAC

March 23-28 2010

Presenter
Presentation Notes
Bullet cluster13Weak lensing rArr Mass not centered on gas13 rArr Confirmation of existence of Dark Matter1313At the same time he applied the virial theorem to the Coma cluster of galaxies and obtained evidence of unseen mass thus starting off the debate on what is now called dark matter 13the virial theorem provides a general equation relating the average over time of the total kinetic energy of a stable system consisting of N particles bound by potential forces with that of the total potential energy where angle brackets represent the average over time of the enclosed quantity Mathematically the theorem stateswhere Fk represents the force on the kth particle which is located at position rk1313The Coma Cluster (Abell 1656) is a large cluster of galaxies that contains over 1000 identified galaxies131933 Zwicky estimated mass of the coma cluster

Dark Matter Understanding

Observational Evidence

Non‐baryonic

Cold massive

Not strongly interacting

Neutral

Stable (or long lived)

WIMP ‐

Particle Nature

Mass

Cross sections

Self annihilation ltA

vgt

Interaction with matter

WIM

P

Measure

X

Carsten

Rott

5

SnowPAC

March 23-28 2010

A Weakly Interacting Massive Particle (WIMP) is generic Dark Matter particle candidate that ldquofitsrdquo

the Dark Matter picture

WIMPs

are prominent Dark Matter candidates

Arise naturally in various well-motivated theories (SUSY Extra Dimensions hellip)

Produced naturally with the correct thermal relic density ldquoWIMP miraclerdquo

Predict signals that might be observable in current and near future experiments

Presenter
Presentation Notes
The recipe for a WIMP is simple just introduce an extension of the SM with13A new stable massive particle that couples to SM particles but with zero electric and color charge and not strongly coupled to Z boson (otherwise excluded by direct detection)

Present abundance

Equilibrium abundance

[Jungman Kamionkowski Griest 1996]

Ways to Study WIMPs

q

q

Carsten

Rott

6

SnowPAC

March 23-28 2010

Thermal relic

Indirect Detection

Nuclear Recoils

ProductionProduction

arXiv0912

3592

WZb em p D

˜

˜

Scattering

Annihilation

Thermal Relic

W Zb e pD

Presenter
Presentation Notes
CDM particles as thermal relic Non relativistic at freeze-out relic density is set by the pair annihilation rate into lighter SM particles13Production of Dark Matter particle in the early universe13All decay except stable particles (LSP for example in SUSY for R-parity conserving scenarios)13Equilibrium density is given by N_eq1313As the universe expanded the temperature of the plasma became smaller than the WIMP mass While annihilation and production reactions remained in equilibrium the number of WIMPs produced decreased exponentially as e1048576m=T (the Boltzmann factor) since only particle-antiparticle collisions with kinetic energy in the tail of the Boltzmann distribution had enough energy to produce WIMP pairs

Indirect Detection with Neutrinos

Carsten

Rott

7

SnowPAC

March 23-28 2010

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 4: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Overwhelming Observational Evidence

Dark Matter already gravitationally ldquoobservedrdquo but hellip

What is it

What are itrsquos properties

1E 0657-56 -

Bullet Cluster

D Clowe et al astro- ph0608407 AJ 648 (2006) L109- 113

Coma Cluster

Carsten

Rott

4

SnowPAC

March 23-28 2010

Presenter
Presentation Notes
Bullet cluster13Weak lensing rArr Mass not centered on gas13 rArr Confirmation of existence of Dark Matter1313At the same time he applied the virial theorem to the Coma cluster of galaxies and obtained evidence of unseen mass thus starting off the debate on what is now called dark matter 13the virial theorem provides a general equation relating the average over time of the total kinetic energy of a stable system consisting of N particles bound by potential forces with that of the total potential energy where angle brackets represent the average over time of the enclosed quantity Mathematically the theorem stateswhere Fk represents the force on the kth particle which is located at position rk1313The Coma Cluster (Abell 1656) is a large cluster of galaxies that contains over 1000 identified galaxies131933 Zwicky estimated mass of the coma cluster

Dark Matter Understanding

Observational Evidence

Non‐baryonic

Cold massive

Not strongly interacting

Neutral

Stable (or long lived)

WIMP ‐

Particle Nature

Mass

Cross sections

Self annihilation ltA

vgt

Interaction with matter

WIM

P

Measure

X

Carsten

Rott

5

SnowPAC

March 23-28 2010

A Weakly Interacting Massive Particle (WIMP) is generic Dark Matter particle candidate that ldquofitsrdquo

the Dark Matter picture

WIMPs

are prominent Dark Matter candidates

Arise naturally in various well-motivated theories (SUSY Extra Dimensions hellip)

Produced naturally with the correct thermal relic density ldquoWIMP miraclerdquo

Predict signals that might be observable in current and near future experiments

Presenter
Presentation Notes
The recipe for a WIMP is simple just introduce an extension of the SM with13A new stable massive particle that couples to SM particles but with zero electric and color charge and not strongly coupled to Z boson (otherwise excluded by direct detection)

Present abundance

Equilibrium abundance

[Jungman Kamionkowski Griest 1996]

Ways to Study WIMPs

q

q

Carsten

Rott

6

SnowPAC

March 23-28 2010

Thermal relic

Indirect Detection

Nuclear Recoils

ProductionProduction

arXiv0912

3592

WZb em p D

˜

˜

Scattering

Annihilation

Thermal Relic

W Zb e pD

Presenter
Presentation Notes
CDM particles as thermal relic Non relativistic at freeze-out relic density is set by the pair annihilation rate into lighter SM particles13Production of Dark Matter particle in the early universe13All decay except stable particles (LSP for example in SUSY for R-parity conserving scenarios)13Equilibrium density is given by N_eq1313As the universe expanded the temperature of the plasma became smaller than the WIMP mass While annihilation and production reactions remained in equilibrium the number of WIMPs produced decreased exponentially as e1048576m=T (the Boltzmann factor) since only particle-antiparticle collisions with kinetic energy in the tail of the Boltzmann distribution had enough energy to produce WIMP pairs

Indirect Detection with Neutrinos

Carsten

Rott

7

SnowPAC

March 23-28 2010

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 5: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Dark Matter Understanding

Observational Evidence

Non‐baryonic

Cold massive

Not strongly interacting

Neutral

Stable (or long lived)

WIMP ‐

Particle Nature

Mass

Cross sections

Self annihilation ltA

vgt

Interaction with matter

WIM

P

Measure

X

Carsten

Rott

5

SnowPAC

March 23-28 2010

A Weakly Interacting Massive Particle (WIMP) is generic Dark Matter particle candidate that ldquofitsrdquo

the Dark Matter picture

WIMPs

are prominent Dark Matter candidates

Arise naturally in various well-motivated theories (SUSY Extra Dimensions hellip)

Produced naturally with the correct thermal relic density ldquoWIMP miraclerdquo

Predict signals that might be observable in current and near future experiments

Presenter
Presentation Notes
The recipe for a WIMP is simple just introduce an extension of the SM with13A new stable massive particle that couples to SM particles but with zero electric and color charge and not strongly coupled to Z boson (otherwise excluded by direct detection)

Present abundance

Equilibrium abundance

[Jungman Kamionkowski Griest 1996]

Ways to Study WIMPs

q

q

Carsten

Rott

6

SnowPAC

March 23-28 2010

Thermal relic

Indirect Detection

Nuclear Recoils

ProductionProduction

arXiv0912

3592

WZb em p D

˜

˜

Scattering

Annihilation

Thermal Relic

W Zb e pD

Presenter
Presentation Notes
CDM particles as thermal relic Non relativistic at freeze-out relic density is set by the pair annihilation rate into lighter SM particles13Production of Dark Matter particle in the early universe13All decay except stable particles (LSP for example in SUSY for R-parity conserving scenarios)13Equilibrium density is given by N_eq1313As the universe expanded the temperature of the plasma became smaller than the WIMP mass While annihilation and production reactions remained in equilibrium the number of WIMPs produced decreased exponentially as e1048576m=T (the Boltzmann factor) since only particle-antiparticle collisions with kinetic energy in the tail of the Boltzmann distribution had enough energy to produce WIMP pairs

Indirect Detection with Neutrinos

Carsten

Rott

7

SnowPAC

March 23-28 2010

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 6: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Present abundance

Equilibrium abundance

[Jungman Kamionkowski Griest 1996]

Ways to Study WIMPs

q

q

Carsten

Rott

6

SnowPAC

March 23-28 2010

Thermal relic

Indirect Detection

Nuclear Recoils

ProductionProduction

arXiv0912

3592

WZb em p D

˜

˜

Scattering

Annihilation

Thermal Relic

W Zb e pD

Presenter
Presentation Notes
CDM particles as thermal relic Non relativistic at freeze-out relic density is set by the pair annihilation rate into lighter SM particles13Production of Dark Matter particle in the early universe13All decay except stable particles (LSP for example in SUSY for R-parity conserving scenarios)13Equilibrium density is given by N_eq1313As the universe expanded the temperature of the plasma became smaller than the WIMP mass While annihilation and production reactions remained in equilibrium the number of WIMPs produced decreased exponentially as e1048576m=T (the Boltzmann factor) since only particle-antiparticle collisions with kinetic energy in the tail of the Boltzmann distribution had enough energy to produce WIMP pairs

Indirect Detection with Neutrinos

Carsten

Rott

7

SnowPAC

March 23-28 2010

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 7: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Indirect Detection with Neutrinos

Carsten

Rott

7

SnowPAC

March 23-28 2010

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 8: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Halo Profiles

Moore NFW Kravtsov

‐

cusp

rs

‐

scale radius

Rsc

‐

85kpc

MooreNFW

KravtsovEinasto

(r) 0rrs

1rrs

( )

Profile rs (Rsc )

Moore 15 3 15 28 027

NFW 1 3 1 20 03

Kravtsov 2 3 04 10 037

Einasto

(r) 2e2

rr2

1

J Einasto Trudy Inst Astroz Alma-Ata 5 87 (1965)Navarro Frenk White Astrophys J 490 493ndash508 (1997)Moore et al Mon Not Roy Astron Soc 310 1147 (1999) [arXivastro-ph9903164]Kravtsov et al Astrophys J 502 48 (1998) [arXivastro-ph9708176]

Rsc

Carsten Rott

8

SnowPAC March 23-28 2010

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 9: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Messengers from Dark Matter Annihilations

+

WW e + rsquos + bb

+ qqZZhellip

Carsten Rott

9

SnowPAC March 23-28 2010

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 10: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Indirect WIMP detectionIndirect WIMP detection

νμSun

ρχ

velocitydistribution

σscatt

Γcapture

ν

interactions

Neutrinos from annihilating Dark Matter captured in the Sun

10

SnowPAC March 23-28 2010Carsten Rott

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 11: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Annhilation Rate

Cross section

Carsten Rott SnowPAC March 23-28 2010

11

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 12: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Why Neutrinos

Neutrinos are unique messengers which allow to probe both

WIMP-Nucleon scattering cross section

Complementary to direct detection experiments

Self-annihilation cross section Lifetime

Complimentary searches to gamma-ray searches

Carsten Rott SnowPAC March 23-28 2010

12

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 13: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Neutrino Dark Matter Searches

Solar Earth HaloNeutrino Flux Scattering

cross‐section

Neutrino Flux

(Scattering

cross‐sections)

Neutrino Flux Self‐

annihilation cross‐section

Muon neutrinos Muon neutrinos Muon neutrinos Cascades

Background off‐source on‐

source

Background simulations Background off‐source on‐

source simulations

MWIMP

~lt100GeV All MWIMPMWIMP

~ltTeV

Carsten Rott

13

SnowPAC March 23-28 2010

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 14: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

IceCube

The Searches covered in this talk use primarily the IceCube 22 string configuration active 2007-2008

Carsten Rott

14

SnowPAC March 23-28 2010

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 15: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

IceCube

Some of them use the IceCube 40 string configuration active 2008-2009

IceCube just completed a very successful deployment season 20092010 and now has 79 strings installed and the low-energy extension Deep Core completed

Carsten Rott

15

SnowPAC March 23-28 2010

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 16: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Backgrounds

High energy muons created in airshowers produce continuous stream of background

p + A

plusmn

(Kplusmn) + other hadrons

+

+

e+

e

Up-going events can be used to obtain ldquocleanrdquo

neutrino sample

Atmospheric neutrinos create irreducible neutrino background to extra terrestrial neutrino fluxes

Atm

Atm Astrophysical

Cosmic Rays

Carsten Rott

16

SnowPAC March 23-28 2010

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 17: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Solar WIMPs

Carsten Rott

17

SnowPAC March 23-28 2010

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 18: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Solar WIMPs

High energy neutrinos (1TeV) do not escape the Sun Indirect dark matter searches from the Sun

are ldquolow-energyrdquo

analysis in neutrino telescopes

Utilize data when the Sun is below the horizon to reduce atmospheric muon background

Consider different annihilation channels

hard W+W-

soft bb

Off-source region can be used to estimate background from data itself

GeV (

GeV (WW

arXiv10011381

Carsten Rott

18

SnowPAC March 23-28 2010

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 19: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Solar WIMP

Event Selection

Sun is below the horizon at South Pole (March ndash

September) ndash

(IceCube livetime = 1043 days)

Event pre-selection at South Pole for Satellite transmission (filter)

Angular selections

Track reconstruction track quality criteria

Final selection via LogLikelihood and advanced analysis tools (SVM ndash

support vector machine)

Carsten Rott SnowPAC March 23-28 2010

19

WIMP 1TeV (hard)

DataSum backgroundCoinc Atm muonsSingle Atm muonsAtm neutrinos

Trig

ger

Onl

ine

Angu

lar

Cuts

Trac

k Q

ualit

y

LLH

SVM

Signal efficiency gt20

Background rejection ~106

IceCube-22 string analysis

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 20: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution

Carsten Rott

20

SnowPAC March 23-28 2010

IceCube

Presenter
Presentation Notes
[65]

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 21: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Final selection

IceCube 22-strings Solar WIMP Search

Carsten Rott

21

SnowPAC March 23-28 2010

Several levels of filtering are applied to remove atmospheric muon backgrounds and utilize a Support Vector Machine SVMs Q1Q2 to define final cut level

Data and simulation agree well

At the final cut level atm neutrinos form biggest background (~56)

Signal efficiency is of order 20 depending on the WIMP mass

Direction of the sun still remained scrambled to this point

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 22: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

IceCube 22-strings Solar WIMP Search

Muon flux in direction of the sun

Examine angular distribution Ψ

for Sun and muon tracks

Angular resolution IceCube-22 (gt500 GeV) 3 degrees

Ψ

Observation consistent with expectations from atmospheric neutrinos upper limit

Carsten Rott

22

SnowPAC March 23-28 2010

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 23: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Solar WIMPs ndash

Spin dependent cross section limit

Obtain limit on the muon flux in direction of the Sun

Constraints are computed in terms of annihilation modes (hard soft)

Assume equilibrium condition and standard halo parameters to obtain constrain on the

WIMP-proton scattering cross-

section

Spin independent cross section tightly constrained in direct detection experiments

Sun ideal to test spin dependent WIMP nucleon scattering cross section

Carsten Rott

23

SnowPAC March 23-28 2010

Phys Rev Lett 102 201302 (2009)arXiv09022460

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 24: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Solar WIMPs -

Kaluza Klein Dark Matter Limit

UED in 5 extra dimensions

WIMP is LKP (KK photon)

Model described by two parameters Δq

and MLKP

Limits on SD WIMP-proton cross section IceCube 22-string and AMANDA 6-year

Carsten Rott

24

SnowPAC March 23-28 2010

arXiv09104480(accepted PRD)

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 25: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Halo WIMPs

Carsten Rott

25

SnowPAC March 23-28 2010

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 26: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Sky map IceCube (22strings)

Carsten Rott SnowPAC March 23-28 2010

26

2757 days of livetime collected with

IceCube

operating

in

the

22‐string

configuration (2007‐2008)

5114

Events

after

selection

from

‐5deg

to +85deg

declination

Track

selection

criteria

have

been

well

established

for

the

IceCube

point

source

search

for

simplicity

and

minimization

of

systematic

effect

we

apply

the

same

selection

criteria

(AstrophysJ701L47‐

L512009)

Theoretical motivation see

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Do we see any effects on Dark Matter in our neutrino sample

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 27: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

2727

Line of sight integral

Expected differential neutrino Flux

Kravtsov

Moore

NFW

DarkSUSY

Measure integrated flux Isotropic emission

Neutrino Flux from annihilations

Carsten Rott SnowPAC March 23-28 2010

Yuksel Horiuchi Beacom Ando (2007)

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 28: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Halo Analysis -

IceCube

Calculate flux signal flux as

function of the distance to the

GC on Northern Hemisphere

(‐5o

ndash 85o)

Optimize

GCGC

--55oo

2525oo

5050oo

7575oo

Atm background

Signal

Optimal signal extend

of

the

region

shows

some

dependence

on

the

halo

model

annihilation

channel

and WIMP mass

Their

overall

behavior

is

however

very

similar

Larger

regions

are

better

and

Ssqrt(B)

flattens out or declines

beginning

with

GC

Kravtsov

NFW

Moore

Carsten Rott

28

SnowPAC March 23-28 2010

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 29: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Halo IceCube 22

Compare regions of equal ldquosizerdquo

(on vs off-source)

No excess flux in the region closer to the galactic center

Rotate regions in 60o

steps as systematic cross check

Distribution is flat

Carsten Rott SnowPAC March 23-28 2010

29

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 30: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Halo Analysis -

IceCube

No anisotropy was observed in IceCube data ndash

constrain the dark matter self-

annihilation cross-section

Limits are at 90 CL

As we probe the outer halo there is only a small dependence on halo profiles

Annihilation into

could also be interpreted as upper limit on total dark matter annihilation cross section (Beacom Bell Mack 2008)

arXiv09125183

Carsten Rott

30

SnowPAC March 23-28 2010

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 31: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

PAMELAPAMELA

FermiFermi

ATICATIC

HESSHESS

Primary Sources eminusaccelerated in supernova remnants Secondary Sources eplusmn

from collisions between cosmic rays amp ISM protons

F Aharonian et al Phys Rev Lett 101 261104 (2008)F Aharonian et al arXiv09050105

M Ackermann ldquoObservation of the extragalactic dif-fuse continuum gamma-ray emission with Fermi LATrdquotalk at TeV Particle Astrophysics 2009 httpwww-confslacstanfordedutevpa09

ee++(e(e+ +

+ e+ e‐‐))

Nature 456 (2008) 362Nature 456 (2008) 362

Fermi Collaboration arXiv09050025

Carsten Rott

31

Moskalenko amp Strong 1998O Adriani et al Nature 458 607 (2009)

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 32: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Halo Analysis -

IceCube

Preliminary IceCube constraints using 275 days of data and the 22 string dataset can probe already some of the preferred parameter

space

Significantly more data has been collected already

arXiv09125183

Carsten Rott

32

SnowPAC March 23-28 2010

Meade et al 2

009

NFW

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 33: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Center IceCube ndash

40 strings

Dark Matter profiles are peaked at the galactic center

As the galactic center (GC) is above the horizon these events are down-going in IceCube

Use down-going starting events to reduce atmospheric muon background

Carsten Rott SnowPAC March 23-28 2010

33

GCoff source on source off source

RA=-180o -20o -

20o 180o

-

Zenith

Optimize the size of the on-source region-

-

compare the amount of events in the on-

and off-source region

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 34: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions from the PAMELA positron excess and Fermi

The Deep Core subdetector is designed to obtain a clean neutrino sample of starting events which will substantially improve our sensitivity for WIMPs in the 100 GeV range

Carsten Rott SnowPAC March 23-28 2010

34

Arxiv09125183See also JHuelss DPG

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 35: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Deep Core

Carsten Rott

35

SnowPAC March 23-28 2010

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 36: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Deep Core

250 m

350

m

Deep Core

extra

veto cap

Normal

HQ

Carsten Rott

36

SnowPAC March 23-28 2010

The Deep Core subdetector has recently been completed and will become operational in spring 2010

It consists of six special strings plus 7 nearest standard IceCube strings

72 m interstring spacing

7 m DOM spacing on string

High QE PMTs (~40 better)

~5x higher eff photocathode density

Clearest ice below 2100 m

λatten

asymp

40-45 m

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 37: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Veto

Top and outer layers of IceCube can be used to veto down-going muons

Three veto string layers surrounding Deep Core

Look for starting events in Deep Core

Veto rejection power

~104 demonstrated with 98 signal eff

~105-106 likely

Carsten Rott

37

SnowPAC March 23-28 2010

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 38: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Conclusions

Neutrino Searches can be used to constrain both the WIMP-proton scattering cross section (Solar WIMPs) and the self-annihilation cross section (Galactic Halo)

IceCube currently provides the worlds best constrain on the Spin

dependent WIMP-

proton cross section for WIMPs in the 100GeV-TeV range

Galactic halo searches can constrain the WIMP self-annihilation cross section significantly

Using the Galactic center we can tightly constrain the WIMP-self annihilation cross section

Deep Core has been deployed and has been performing well during its commissioning it will be fully integrated in IceCube physics data taking in April

Deep Core will significantly increase IceCube sensitivity to WIMP masses around and below 100GeV

Carsten Rott SnowPAC March 23-28 2010

38

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 39: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Backup Slides

Carsten Rott

39

SnowPAC March 23-28 2010

Presenter
Presentation Notes
Pamela13ATIC AMS13

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 40: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

arXiv09061615

Sun-Centered Skymap ndash

AMANDA IIAMANDA-II953 days livetime4665 total events

Maximum likelihood search reveals 08

downward fluctuation

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 41: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

WIMPs in the Earth

WIMP annihilation in the Earth

Muon neutrinos provide good pointing resolution

Ψ

Carsten Rott

41

SnowPAC March 23-28 2010

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 42: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Digital Optical Module (DOM)

Measure individual photon arrival timebull 2 ping-ponged four-channel ATWDs

bull

Analog Transient Waveform Digitizerbull 200-700 Megasamplessbull 400 ns rangebull 400 pe 15 ns

bull fADC (fast lsquoADCrsquo)bull 40 Megasamplessbull 64 s range

bull Dark Noise rate ~ 350 Hz bull Local Coincidence rate ~ 15 Hzbull Deadtime lt 1bull Timing resolution le

2 ns

Oslash~36 cm

10

inch Hamamatsu PMT (R-7081-02)

Digitized Waveform

Carsten Rott

42

SnowPAC March 23-28 2010

bins

V

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 43: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Carsten Rott CCAPP Symposium 2009

43

KKT unitarity bound

BBM

How large can the self‐annihilation cross‐section ltA

vgt be

Yuksel Horiuchi Beacom Ando (2007)Yuksel Horiuchi Beacom Ando (2007)

Theoreticalcosmological constraints

KKT ‐

Kaplinghat Knox Turner (2000)

ldquoDM annihilation flattens cusprdquo

Unitarity bound

Unitarity of the scattering matrix

Natural scale

DM is thermal relic of early universe

Derived limitssensitivity

BBM ‐

Beacom Bell Mack (2008)

Cosmic time‐integrated annihilation

MW Halo Isotropic

J()(immediate neighborhood)

MW Halo Average

Average flux from halo

MW Halo Angular

30o

cone around GC3292010

43

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 44: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Galactic Center

Neutrino constraints from IceCube are very competitive and start to probe preferred regions PAMELA positron excess and Fermi

Carsten Rott SnowPAC March 23-28 2010

44

See also JHuelss DPGMeade et al 2009

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 45: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

WIMP Detection Summary

Direct Detection

Recoil effects ‐

WIMP scattering of nucleons

Indirect Detection

Neutrinos ndash

annihilation signals from WIMPs accumulated in

the Sun or Earth

Photons Neutrinos ndash

Milky Way Halo Cosmic Flux hellip

Anti‐matter (D p‐bar e+ e-) ndash local neighborhood (few kpc)

Production

LHC Tevatron ILC hellip

WIM

P‐Nucleon

Scatteringcross‐section

WIM

P Self‐annihilationcross‐section

Carsten Rott

45

SnowPAC March 23-28 2010

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 46: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Neutrino Detection -

Examplesta

u

ele

ctro

n

m

uon

Simulation

produce long

tracks

Angular resolution ~ 10

e CC x NC cause showers

~ point sources -gtrsquocascadesrsquo

Good energy resolution

lsquodouble bang events

Other

topologies under study

Carsten Rott

46

SnowPAC March 23-28 2010

Data

Presenter
Presentation Notes
Different topological signatures

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 47: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

SnowPAC March 23-28 2010

47

Cascade reconstruction

Carsten Rott

Make use of the full waveform information in IceCube

Take inhomogeneity of the ice into account

Photonics package is used to construct ldquotabulated delay time distributionsrdquo

Maximum log reconstruction

~30deg 100TeV ndash

10PeV~65deg 10-100GeV

For 40 string detector study case

EMiddell J McCartin MDrsquoAgostino [IceCube] ICRC 2009

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 48: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

Carsten Rott 48

Systematic uncertainties Halo Analysis

Signal acceptance

Uneven ldquoexposurerdquo

(negligible)

Ice properties DOM efficiency (~20)

MCdata disagreement (horizontal events)

Background

Majority of systematics cancel out (as we use the data itself)

ldquoexistingrdquo

large scale anisotropy

-

Uneven ldquoexposurerdquo

-

Neutrino anisotropy caused by cosmic ray anisotropy

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 49: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

4949

Uneven exposure

Track reconstruction efficiency varies in detector coordinates

In equatorial coordinates this reconstruction efficiency is smeared out (as the detector rotates)

Uneven detector up-time can however reduce this smearing effect

Detector down-time correlates with satellite visibility (maintenance mode)

Detector uptime in sidereal days defines this impact

100

90

IceCube up-time sketchSatellite pass

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 50: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

5050

Uneven exposure

Track reconstruction efficiency shows ldquomirror symmetryrdquo

on source

off source

transitio

n

Uneven exposure systematic uncertainty is on the order of the difference between the two graphs ~01

Total systematic effect ~ 3

Normal +Normal +180deg rotated180deg rotated

NN ~ 01

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 51: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

51

4 TeV4 TeV

62 TeV62 TeV

12 TeV12 TeV

50 TeV50 TeV

300 TeV300 TeV

Science 314439Science 314439--44320064432006

51

Celestial Cosmic Ray intensity map at different energies (TIBET)rlm

Neutrino energy is roughly 110-

130 of the shower energy (cosmic ray primary)

most relevant energy region

PhysRevD531314-13231996See also Abbasi

et al ICRCrsquo09

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy
Page 52: 2010 Snowbird Workshop on Particle Astrophysics, Astronomy & Cosmology … · 2010-12-08 · Dark Matter Searches with IceCube Carsten Rott (for the IceCube Collaboration) carott@mps.ohio-state

5252

Cosmic ray anisotropy

Cosmic ray anisotropy could also cause anisotropy in atmospheric neutrinos

At relevant energies the anisotropy of cosmic rays is a fraction of a percent

Onoff-source region has a background expectation of 1300 neutrino candidate events

For an anisotropy of 02 a maximum effect of 26events -gt 4

syst uncertainty can be

expected

  • Dark Matter Searches with IceCube
  • Overview
  • Motivation
  • Overwhelming Observational Evidence
  • Dark Matter Understanding
  • Ways to Study WIMPs
  • Indirect Detection with Neutrinos
  • Halo Profiles
  • Messengers from Dark Matter Annihilations
  • Indirect WIMP detectionIndirect WIMP detection
  • Annhilation Rate Cross section
  • Why Neutrinos
  • Neutrino Dark Matter Searches
  • IceCube
  • IceCube
  • Backgrounds
  • Solar WIMPs
  • Solar WIMPs
  • Solar WIMP
  • Experimentally verify that neutrinos are reconstructed correctly and test pointing resolution
  • Slide Number 21
  • IceCube 22-strings Solar WIMP Search
  • Solar WIMPs ndash Spin dependent cross section limit
  • Solar WIMPs - Kaluza Klein Dark Matter Limit
  • Galactic Halo WIMPs
  • Sky map IceCube (22strings)
  • Slide Number 27
  • Galactic Halo Analysis - IceCube
  • Galactic Halo IceCube 22
  • Galactic Halo Analysis - IceCube
  • Slide Number 31
  • Galactic Halo Analysis - IceCube
  • Galactic Center IceCube ndash 40 strings
  • Galactic Center
  • Deep Core
  • Deep Core
  • Veto
  • Conclusions
  • Backup Slides
  • Sun-Centered Skymap ndash AMANDA II
  • WIMPs in the Earth
  • Digital Optical Module (DOM)
  • How large can the self-annihilation cross-section ltsAvgt be
  • Galactic Center
  • WIMP Detection Summary
  • Neutrino Detection - Examples
  • Cascade reconstruction
  • Systematic uncertainties Halo Analysis
  • Uneven exposure
  • Uneven exposure
  • Slide Number 51
  • Cosmic ray anisotropy

Snowbird Conference Center Banquet Menus · Snowbird Conference Center Banquet Menus Above the Clouds. Beyond the Expected. Snowbird Meetings. 2018. Catering Information ... To ensure

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IRA April 2006 D.F. Cowen/IceCube Collab. Beyond IceCube Beijing UHE Workshop 1 Beyond IceCube @ the South Pole Outline Introduction: Optical vs. Radio

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GZK ’s and their Detection with IceCube Interactions Interactions Results Results Implications for the IceCube Implications for the IceCube Summary Summary

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Snowbird User Research

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Snowbird Invitation Annual Conference

Snowbird Invitation Annual Conference

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Snowbird Resort Snowbird, Utah · : DeAnna Torres, Alan Vasquez, Angie Lule, Jesse Leos, Selene Moron, and Kareli Flores

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Tramigo™ T23 Fleet - P.K. Snowbird

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Cosmic Rays in IceCube - L'Irfu, Institut de Recherche sur ...irfu.cea.fr/Meetings/TeVPA/slides/19_07_pm_Berghaus.pdf · Patrick Berghaus Cosmic Rays in IceCube IceCube Components

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View the brochure - SnowbirD

View the brochure - SnowbirD

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snowbird guide (2008)

snowbird guide (2008)

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Snowbird Jr m

Snowbird Jr m

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IceCube Dust Loggers

IceCube Dust Loggers

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IceCube analysis

IceCube analysis

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IceCube By:Nicole Baker ~Waterloo What is IceCube? IceCube is a one-cubic-kilometer international high- energy neutrino observatory being built and installed

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SNOWBIRD DINING FACILITIES

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IceCube Project Monthly Report February 2008 Accomplishmentsicecube.wisc.edu/icecube/static/reports/monthly/February_2008.pdf · IceCube Project Monthly Report February 2008 Accomplishments

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Hakvoort Shipyard Snowbird

Hakvoort Shipyard Snowbird

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