Summary WG4 – Neutrino Astronomy experimental part

Summary WG4 – Neutrino Astronomy experimental part Mieke Bouwhuis: Results from ANTARES Georgio Riccobene: Results from NEMO and KM3NeT Dave Besson: Radio detection Doug Cowen: Tau neutrino detection in IceCube Ty de Young: Novel tau signatures in neutrino telescopes Julia Becker: AMANDA flux results and interpretation Elisa Resconi: IceCube: multiwavelength approach + many posters extend reach: (sky coverage, energy coverage, -id …) improve sensitivities: (stacking, - correlation…) Lutz Köpke University of Mainz

reconstruction with one line ANTARES Mieke Bouwhuis full detector data taking 2007+

“typical” downgoing muons … also several upgoing muons probably muon bundle single muon

Zenith angle of atmospheric muons

ANTARES Toulon 2400 m NESTOR NEMO Capo Passero 3450 m Pylos 3800:4000 m Status of the NEMO Project Advantages: Deep, low bioluminescence, weak currents, little sedimentation full tower 2007 TDR KM3NeT 2009 cost < 200 M€ Georgio Riccobene

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 David Besson Future: Hybrid detectors (optical, radio, acoustic) • Points of cautions: • 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

wild ideas florish … radio antenna Europa

Advantages of Tau Neutrinos D. Cowen & Ty de Young  appreciable nt flux at source ne:nm:nt::1:2:0 flux rate at detector ne:nm:nt::1:1:1  for E > ~1 TeV nt low background for some topologies atmospheric neutrino oscillation and open charm negligible …  rich set of signatures …  4p acceptance at E(nt) < ~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 …

“Lollipop” – half of a double bang relatively dim track Beacom, Bell, Hooper, Pakvasa & Weiler  detection with IceCube “classic double bang”  νN interaction : 50 m/PeV  decay Learned & Pakvasa 1995

Tau topologies ….a first look ..look at green topologies

Toy-MC: Looks encouraging DOM Waveform needs full simulation! Double Pulse topology  fully simulated waveform 75 TeV  (~300 TeV nt): cascade 1 cascade 2 sum  MC truth discrimination not always that obvious …

Energy loss mechanisms l l (= μ,τ) l γ l τ μ EM showers l e+ e- l l hadronic shower

μ τ Muons are brighter than ’s Sugar daddy topology → track suddenly brightens track length sufficient Can we see it? energy resolution Ty de Young, Cowen, Razzaque, astro-ph/0608486

Julia Becker 6x 10-8 GeV cm-2 s-1 improvement due to stacking Search for single point sources AMANDA: 4282 events in 5 years  no significant signal  limit map preliminary 90% confidence levelflux upper limits for the northern hemisphere in 0.5 deg bins (15% systematic error included) Source stacking(model-dependent!!) allows for <O(10) sensitivity improvement …

Nr of n 1 2001 2002 2000 2003 Time Time correlation studies Photon Rate (counts/sec) dFatm(t)/dt = 1 / year 3o sky-bin 1 n / day sky-bin ~ 3 10 -3 How can we discriminate these events ? What can we learn from photon observations? Elisa Resconi

Careful! Very low statistics! To turn neutrino detector to a all-sky 24/24 monitor and trigger:  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 continuous TeV-gamma sporadic …. “orphans”: TeV-gamma but no x-ray  define and “code” definition of a flare  reconstruct neutrino online 3 month test AMANDA/Magic this year…

Elevated levels or flares : ~ 15 % + 3 Rchar Characteristic level (band) Depends on: source + detector TeV- curves very sporadic, historical light curves: under construction All-Sky-Monitor, Maximum-Likelihood-Blocks, Characteristic level zoom Mkn 421 Elisa Resconi

AMANDA AMANDA 4 year limit assuming E-2: Hill et al., Neutrino 2006 Diffuse limits Differential limits difficult to obtain  limits depend on assumed spectral index Nellen,Mannheim & Biermann 1993 Stecker & Salamon 1996 (x-ray) Stecker 2005 (-ray) …exclude Stecker&Salomon 96 AGN flux, but not Stecker 2005

x diffuse  flux flux sources up to redshiftzmaxabsorption factor Both ,  visible (x < 0.3) only  visible (1 < x < 10) Diffuse flux of TeV Blazars conservative estimate:

Maximum contribution from TeV blazars Test specific models! astro-ph/0607427

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

Summary WG4 – Neutrino Astronomy experimental part