IceCube Outlook for Neutrino Detection at the South Pole S Robbins University of Wuppertal Moriond - “Contents and Structures of the Universe” La Thuile, Italy, March 2006
Scientific Goals • IceCube Status • AMANDA Results Amundsen-Scott South-Pole Station
Alabama University, USA • Bartol Research Institute, Delaware, USA • Pennsylvania State University, USA • UC Berkeley, USA • UC Irvine, USA • Clark-Atlanta University, USA • University of Alaska, Anchorage, USA • Univ. of Maryland, USA • IAS, Princeton, USA • University of Wisconsin-Madison, USA • University of Wisconsin-River Falls, USA • LBNL, Berkeley, USA • University of Kansas, USA • Southern University and A&M College, Baton Rouge, USA The IceCube Collaboration Japan USA (14) Europe (15) • Chiba University, Japan • University of Canterbury, Christchurch, NZ New Zealand • Universite Libre de Bruxelles, Belgium • Vrije Universiteit Brussel, Belgium • Université de Mons-Hainaut, Belgium • Universiteit Gent, Belgium • Humboldt Universität, Germany • Universität Mainz, Germany • DESY Zeuthen, Germany • Universität Dortmund, Germany • Universität Wuppertal, Germany • MPI Heidelberg, Germany • Uppsala University, Sweden • Stockholm University, Sweden • Imperial College, London, UK • Oxford University, UK • Utrecht University, Netherlands ANTARCTICA
Detect neutrinos from the sources of cosmic-rays Super Nova Remnants Solar WIMPs Search for neutrinos from dark matter annihilations Active Galactic Nuclei New Physics Search for neutrinos from cosmological events Gamma Ray Bursts Magnetic Monopoles Physics Goals
Observing Neutrinos • Fermi acceleration of protons gives particle spectrum • dNp/dE~ E-2 • Neutrino production at source: • p+ or p+p collisions gives pions • ± -> ± + • ± -> e± + + e • Neutrino flavors: • e : : • 1:2:0 generic sources • 1:1:1 after oscillations
IceTop air shower array 80 pairs of ice Cherenkov tanks IceCube (deep ice) 80 strings of 60 optical modules 17 m between optical modules 125 m between strings 1 km3 (1 Gton) detector! AMANDA 19 strings, 677 OMs total ø 200m, height 500m IceCube
energy deposited in OM μ νμ W X X’ time recorded on OM detection principle Optical module • Mean - angle is ~0.7o at 1TeV • Muon travels a large distance • Interaction can be outside the detector • Active volume is much larger than the detector Proposed by Markov 1960 ~10-20 m
νe,τ e,τ energy deposited in OM W N X νμ,e,τ νμ,e,τ Z N X time recorded on OM e & detection principle Optical module Charged-current interactions: Neutral-current interactions:
Ice Properties • Ice not uniform in depth (e.g. dust layers) • Important to understand ice for analysis Mean scattering length: 25m Mean absorption length: 110m
Light Propagation • Cherenkov cone from muon tracks • Use timing information, accounting for propagation Homogeneous ice Depth Dependent ice properties
Drill tower 5 MW Hot water generator Hose reel IceTop tanks Hot-water drilling
IceCube Today • 2004/2005 season • New hot water drill • First string deployed (string 21) • Four IceTop stations installed (16 OMs) • 60 OMs in deep ice, all 60 functioning • 2005/2006 season • Modified drill • 8 strings deployed • 12 IceTop stations installed • 480 OMs in deep ice and 48 OMs in IceTop Only IceTop tank AMANDA 500 m InIce string & IceTop
9 string Downgoing IceCube event Neutrino candidate “String 21” Data First IceCube string, deployed January 2005
IceTop air shower array 80 pair of ice Cherenkov tanks IceCube (deep ice) 80 strings of 60 optical modules 17 m between optical modules 125 m between strings 1 km3 (1 Gton) detector! AMANDA 19 strings, 677 OMs total ø 200m, height 500m AMANDA
“Diffuse Limits” • Measure the neutrino energy spectrum • Search for a break in the spectrum Results from one year (2000) of data Consistent with Atmospheric neutrino expectation Some AGN models excluded at 90% CL : Szabo-Protehoe 92 Stecker, Salamon. Space Sc. Rev. 75, 1996 Protehoe. ASP Conf series, 121, 1997 E2μ(E) < 2.6·10–7 GeV cm-2 sr-1 s-1
2000-2003 data: 807 days livetime • 3329 neutrino events • Largest significance = 3.4 (92% chance occurrence) • No significant excess observed Point Source Search Neutrino sky map:
+1 hour 10 min -1 hour Year Detector NBursts NBG, Pred NObs Event U.L. 1997 B-10 78 (BT) 0.06 0 2.41 1998 B-10 94 (BT) 0.20 0 2.24 1999 B-10 96 (BT) 0.20 0 2.24 2000 A-II (2 analyses) 44 (BT) 0.83/0.40 0/0 1.72/2.05 97-00 B-10/A-II 312 (BT) 1.29 0 1.45 2000 A-II 24 (BNT) 0.24 0 2.19 2000 A-II 46 (New) 0.60 0 1.88 1.47 A-II 114 (All) 1.24 0 2000 Neutrinos from GRBs Using space and time coincidence leads to a very low background. No observed signal Only ~1 order of magnitude above Waxmann&Bahcall prediction
Earth Detector Solar WIMPs • Neutralinos captured in the Sun • These annihilate producing quarks and leptons • And neutrinos, which we search for with IceCube χ + χ → ν + ν (+…) Silk, Olive and Srednicki, ’85Gaisser, Steigman & Tilav, ’86 Freese, ’86; Krauss, Srednicki & Wilczek, ’86 Gaisser, Steigman & Tilav, ’86
Limits on muon flux from Sun IceCube Best-Case Neutralinos from the Sun data from 2001 Sun
Conclusions • 2005/6 was a successful deployment season • Now have in total 604 optical modules installed • Only ~1% failure rate • IceCube is on track for 1km3 neutrino observatory • AMANDA has taken 10 years of data • AMANDA continues to produce physics results • No extraterrestrial neutrinos observed so far • Stay tuned…
