UHE Neutrino Astronomy

Shigeru Yoshida

Chiba University

http://www-ppl.s.chiba-u.jp/~syoshida/

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Outline

UHE emission – What it can tell

Theoretical Bound of fluxes

Extremely High-Energy generation

Cosmic detection – the current status

IceCube : reachable to EHE universe

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TeV sources!

cosmic rays

/////////////////

Physics motivation

origin and acceleration of cosmic rays understand cosmic cataclysms find new kind of objects?

neutrino properties ( , cross sections ..)

dark matter (neutralino annihilation)

• tests of relativitiy ....• search for big bang relics ...• effects of extra dimension etc. ...

Active Galaxies: Jets

VLA image of Cygnus A

20 20 TeV gamma raysTeV gamma raysHigher energies obscured by IR lightHigher energies obscured by IR light

radiationenvelopingblack hole

black hole

You cannot expect too many !

p (p,n) 2

e

TeV/EGRET observations !!

Cosmic Ray observations! Synchrotron

coolingYou cannot expect too high energies

Theoretical bounds

atmospheric

W&B W&B

MPRMPR

DUMAND test string

FREJUS

NT-200

MACRO opaque for neutrons

Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999) derived from known limits on extragalactic protons + -ray flux

neutrons can escape

Suppressed by Synchrotron Cooling

EHE(Extremely HE) Synchrotron cooling of … Production sites with low B

Intergalactic space!!

•GZK Production•Z-burst•Topological Defects/Super heavy Massive particles

GZK Neutrino ProductionGZK Neutrino Production

2.725 K

411 photons / cm3

Gamma Beam Energy (GeV)

Cro

ss S

ect

ion (mb)

0.1

0.01

γ + p→Δ （1232）→ π o p or π + n

Gamma Beam Energy (GeV)

Cro

ss S

ect

ion (mb)

0.1

0.01

γ + p→Δ （1232）→ π o p or π + n

Gamma Beam Energy (GeV)

Cro

ss S

ect

ion (mb)

0.1

0.01

γ + p→Δ （1232）→ π o p or π + n

0.6 x 10-27 cm2

γp

n p

π＋ μ＋ ν

e＋

νγ

E = 10 20 eV

E 0.8 x 10 20 eV ~

Conventional Mechanism of EHE neutrinos!!Conventional Mechanism of EHE neutrinos!!　　

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Yoshida and Teshima 1993Yoshida, Dai, Jui, Sommers 1997

GZK fluxes

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γ spectral injection index

m activity evolution index

zmax z of formation of sources

ΩM density of matter

Ho Hubble constant

B intergalactic magnetic field

ηLρL/ηoρo local enhancement

Emax maximum acceleration energy in source

Parameters Orientative order of magnitude

[1-3]

[3-5]

[1-4]

[0.2-1]

[50-80 Km/s/Mpc]

[B≤1nG]

[?]

[E max >4 1020 eV]

Parameters involved in calculation. Predicted fluxes.

(Diego González-Díaz, Ricardo Vázquez, Enrique Zas 2003)

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CR and ν fluxes for different models

(Diego González-Díaz, Ricardo Vázquez, Enrique Zas 2003)

EHE Constraints by CR/

Deciding factors•Source Evolution•Extension of source distribution•Local source enhancement?

Z-bursts Concept

CRs extending to superEHEs!

Z-burst constraints

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(Yoshida, Sigl, Lee 1998)

EHE Neutrino FluxesRESCEU 2003

Cosmic UHE detection

Neutrino Telescopes – Antares, AMANDA, IceCube etc.

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neutrino

muon

Cherenkov

light cone

Detectorinteraction

•Infrequently, a cosmic neutrino is captured in the ice, i.e. the neutrino interacts with an ice nucleus

•In the crash a muon (or electron,

or tau) is produced

•The muon radiates blue light in its wake

•Optical sensors capture (and map) the light

Optical CherenkovOptical CherenkovNeutrino Telescope ProjectsNeutrino Telescope Projects

NESTOR Pylos, Greece

ANTARESLa-Seyne-sur-Mer, France

BAIKAL Russia

DUMAND Hawaii

(cancelled 1995)

AMANDA, South Pole, Antarctica

NEMOCatania, Italy

Demonstrator LineNov 1999- Jun 2000

42°59 N, 5°17 E Depth 1200 m

ANTARES 0.1km2 Site42°50 N, 6°10 E Depth 2400 m

Existing CableMarseille-Corsica

Marseille

ToulonLa Seyne sur Mer

New Cable (2001)La Seyne-ANTARES

ANTARES Deployment Sites

~ 40 deployments and recoveries of test lines for site exploration0.1 km2 Detector with 900 Optical Modules , deployment 2002- 2004

ThetysThetys

ANTARES Layout• 12 lines• 25 storeys / line• 3 PMT / storey

~60-75 m

350 m

100 m

14.5 m

Junctionbox

Readout cables

40 km toshore

Laser calibration at the CPPM dark room

Optical Optical fibresfibres

t1

t2

t3

Optical Splitter

Laser

Optical beacon

Cylinder

Amundsen-Scott Station South Pole

Optical module

1996-2000

AMANDA II Detector

Detection of e , ,

~ 5 m

Electromagnetic and hadronic cascadesO(km) long muon tracks

direction determination by cherenkov light timing

15 m

The highest energy event (~200 TeV)

300 m

Excess of cosmic neutrinos? Not yet ...

cascades (2000 data)

„AGN“ with 10-5 E-2

GeV-1 cm-2 s-1 sr-1

.. for now use number of hit channels as energy variable ...

muon neutrinos (1997 B10-data)accepted by PRL

cuts determined by MC – blind analyses !

talk HE 2.3-4

sky subdivided into 300 bins (~7°x7°)

below horizon:mostly fake events

above horizon: mostly atmospheric ‘s 697 events observed above horizon 3% non-neutrino background for > 5° cuts optimized in each declination band

PRELIMINARY

Point source search in AMANDA II

Search for excess events in sky bins for up-going tracks

talk HE 2.3-5

no clustering observed - no evidence for extraterrestrial neutrinos ...

Theoretical bounds and future

atmospheric

W&B W&B

MPRMPR

DUMAND test string

FREJUS

NT-200

MACRO

NT-200+

AMANDA-II

IceCube

AMANDA-97

AMANDA-00

opaque for neutrons

Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999) derived from known limits on extragalactic protons + -ray flux

neutrons can escape

IceCube

1400 m

2400 m

AMANDA

South Pole

IceTop

Skiway

80 Strings4800 PMT Instrumented volume: 1 km3 (1 Gt)IceCube is designed to detect neutrinos of all flavors at energies from 107 eV (SN) to 1020 eV

Talks/Poster by H. Miyamoto this evening

IceCube (1km3 underground observatory)

Sensitive to 10-2 ~ 10-3 of the WB bound

EHE( ~EeV) -- Almost reachable!GZK, Z-burst, TD... New Physics?

Secondary / detection

Eµ=10 TeV ≈ 90 hits Eµ=6 PeV ≈ 1000 hits

How EHE events look like

The typical light cylinder generated by a muon of 100 GeV is 20 m, 1PeV 400 m, 1EeV it is about 600 to 700 m.

EHE (EeV or even higher) Neutrino Events

Arriving Extremely Horizontally

• Needs Detailed Estimation• Limited Solid Angle Window

(NA)-1 ~ 600 (/10-32cm2) -1(/2.6g cm-3) -1 [km]

Involving the interactions generating electromagnetic/hadron cascades

N X e+e-

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e

e

e/

e/

Weak

Weak

Weak

Inco

min

gProducts

Weak

Weak

Weak

Cascades

Cascades

Decay DecayWeak

Pair/decayBremss

Pair Pair PhotoNucl.

PhotoNucl.DecayPair Pair

PairBremssDecay

DecayWeak

DecayDecayDecay

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Tau(Neutrinos) from

Suppression

By decay

Muon(Neutrinos) from

Nadir Angle

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Upward-going Downward going!!

Atmospheric muon! – a major backgrondBut so steep spectrum

１．４ｋｍ

１ｋｍ

Downward

Upward

Ice

Rock

ν

ν

±π

γ

γ

γν

+e －e１ｋｍ

+e －e

lepton

lepton

EHE events!

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Down-going events dominate…

1400 m

2800 m

11000mUp Down

Atmospheric is attenuated faster…

Flux as a function of energy deposit in km3

dE/dX~E E~XbE

Flux as a function of energy deposit in km3

dE/dX~E E~XE

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Intensity of EHE and GZK m=4 Zmax=4

I(E>10PeV) I(E>10PeV) RATE [/yr/km2]

Down 5.90 10-19 5.97 10-19 0.37Up 3.91 10-20 6.63 10-20 0.03

I(E>10PeV) Energy Deposit

I(E>10PeV) Energy Deposit

Down 4.75 10-19 3.28 10-19 0.25m=7 Zmax=5Down

7.21 10-17 4.83 10-17 37.9

Atm 1.74 10-19 0.05

[cm-2 sec-1]

IceCube EHE Sensitivity90% C.L. for 10 year observation

Summary

UHE fluxes are constrained by /CR fluxes. A detection beyond this limit would imply a new class of astronomical objects.

EHE fluxes are constrained by EGRET /UHECR fluxes and by the synchrotron cooling of ’s. The loophole to this bound would be the GZK cosmogenic neutrinos with intensity of 10-7~10-8 GeV /cm2 sec sr.

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Summary (Cont’d)

AMANDA observatory is getting to reach to its sensitivity to the WB bound. The other telescopes in northern hemisphere would reaches the similar sensitivity.

IceCube observatory would be sensitive to 10-2 of the WB bound. The EHE sensitivity is comparable to the GZK neutrinos fluxes: 3x10-8 GeV /cm2 sec sr in 10 years observation.

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