Summary WG4 – Neutrino Astronomy experimental part

Mieke Bouwhuis: Results from ANTARESGeorgio Riccobene: Results from NEMO and KM3NeTDave Besson: Radio detectionDoug Cowen: Tau neutrino detection in IceCubeTy de Young: Novel tau signatures in neutrino telescopesJulia Becker: AMANDA flux results and interpretationElisa Resconi: IceCube: multiwavelength approach

Lutz KöpkeUniversity of Mainz

+ many posters

extend reach: (sky coverage, energy coverage, -id …)improve sensitivities: (stacking, - correlation…)

ANTARES

Mieke Bouwhuis

reconstruction with one line

full detector data taking 2007+

“typical” downgoing muons

single muon probably muon bundle

… also several upgoing muons

Zenith angle of atmospheric muons

Status of the NEMO Project

Georgio Riccobene

Capo Passero 3450 m

Toulon 2400 m

Pylos 3800:4000 m

ANTARES

NEMO

NESTOR

Advantages:

Deep, low bioluminescence, weakcurrents, little sedimentation

full tower 2007

TDR KM3NeT 2009 cost < 200 M€

NEMO-km3 detector design study

20 m

40 m

…similar number of PMT’s, towers as IceCube… 100 km from shore

Modular, rigid structures with 4 PMTs that unfolds …

Philosophy: reduce number of structures and

underwater connections; operate by ROV

Radio detection

Points of cautions: 1) presented upper limits can `float’ horizontally (no energy resolution),2) different model parameters used for different modes, 3) 90% vs. 95% C.L. limits, 4) results depend on binning

Future: Hybrid detectors(optical, radio, acoustic)

David Besson

wild ideas florish …

Europa

radio antenna

Advantages of Tau Neutrinos

appreciable flux

at source e::::1:2:0 flux rate at detector e::::1:1:1

for E > ~1 TeV low background for some topologies

atmospheric neutrino oscillation and open charm negligible …

rich set of signatures …

4acceptance at E() < ~1014-15 eV due to regeneration

very clean tag for cosmological neutrino origin !

…. but geometrically coarse detectors, low event rates, limited energy range, branching ratio …

D. Cowen & Ty de Young

detection with IceCube

: 50 m/PeV

νN interaction

decay

“classic double bang”

Learned & Pakvasa 1995

“Lollipop” – half of a double bang

Beacom, Bell, Hooper, Pakvasa & Weiler

relatively dim track

Tau topologies

..look at green topologies

….a first look

Double Pulse topology

fully simulated waveform 75 TeV (~300 TeV ):

cascade 1 cascade 2 sum MC truth

DOM Waveform

discrimination not always that obvious …

Toy-MC:Looks encouraging

needs full simulation!

ll

ll

ll

γ

e+

e-

hadronicshower

( = μ,τ)l

EMshowers

μ

Energy loss mechanisms

τ

Muons are brighter than ’s

τ

μ

→ track suddenly brightens

Can we see it?

Sugar daddy topology

track length sufficient

Ty de Young, Cowen, Razzaque, astro-ph/0608486

energy resolution

Search for single point sources

90% confidence level flux upper limits for the northern hemisphere

in 0.5 deg bins (15% systematic error included)

AMANDA: 4282 events in 5 years no significant signal limit map

improvementdue to stacking

6x 10-8 GeV cm-2 s-1

Source stacking (model-dependent!!) allows for <O(10) sensitivity improvement …

preliminary

Julia Becker

2000 2001 2002 2003

1

Nr of

Time

datm(t)/dt = 1 / year 3o sky-bin

1 / day sky-bin ~ 3 10 -3

How can we discriminate these events ?

What can we learn from photonphoton observations?

Photon Rate (counts/sec)

Time correlation studies

Elisa Resconi

Careful! Very low statistics!

test well defined hypotheses, do blind analyses, define statistical interpretation beforehand!

sample, time periods determined a priori in the time periods / atmospheric expected

intelligently select sources to monitor obtain/analyze/interpret photonic data (x-ray, gamma)

x-ray monitoring continuousTeV-gamma sporadic ….“orphans”: TeV-gamma but no x-ray

define and “code” definition of a flare reconstruct neutrino online

To turn neutrino detector to a all-sky 24/24 monitor and trigger:

3 month test AMANDA/Magic this year…

Elisa Resconi

All-Sky-Monitor, Maximum-Likelihood-Blocks, Characteristic level zoom Mkn 421

Characteristic level (band)Depends on: source + detector

Elevated levels or flares : ~ 15 %

+ 3

Rchar

TeV- curves very sporadic, historical light curves: under construction

AMANDA

Diffuse limits

112

82 108.8

srsGeVcm

E AMANDA4 year limitassuming E-2:

Hill et al., Neutrino 2006Nellen,Mannheim & Biermann 1993

Stecker & Salamon 1996 (x-ray)

Differential limits difficult to obtain limits depend on assumed spectral index

…exclude

Stecker&Salomon 96 AGN flux, but not Stecker 2005

Stecker 2005 (-ray)

Diffuse flux of TeV Blazars

conservative estimate:

Both , visible (x < 0.3)only visible (1 < x < 10)

x

diffuse flux flux sources up to redshift zmax absorption factor

Maximum contribution from TeV blazars

astro-ph/0607427

Test

spe

cific

mod

els!

Experimental summary(summary) of WG4

Extend reach:

– Northern hemisphere detectors (Antares 2007+, TDR km3NET 2009)– Further extend energy range (radio, acoustics ….)– Ideas to identify -neutrinos in many topologies

Extend sensitivities:

– stacking techniques (assume analogous behaviour, - correlation)– Correlation with x-ray or TeV flares; -telescope triggers?– Investigate specific models