IceCube S Robbins University of Wuppertal Moriond - “Contents and Structures of the Universe” La...
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Transcript of IceCube S Robbins University of Wuppertal Moriond - “Contents and Structures of the Universe” La...
IceCubeIceCube
S Robbins
University of Wuppertal
Moriond - “Contents and Structures of the Universe”
La Thuile, Italy, March 2006
Outlook for NeutrinoDetection at the South Pole
Outlook for NeutrinoDetection at the South Pole
USA (14)USA (14)Europe (15)Europe (15)
JapanJapan
New ZealandNew Zealand
• 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
• 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
• 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
• 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
• 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
• Universität Wuppertal, Germany• MPI Heidelberg, Germany • Uppsala University, Sweden• Stockholm University, Sweden• Imperial College, London, UK• Oxford University, UK• Utrecht University, Netherlands
• University of Canterbury, Christchurch, NZ• University of Canterbury, Christchurch, NZ
ANTARCTICA
The IceCube Collaboration
• Chiba University, Japan• Chiba University, Japan
Physics GoalsDetect neutrinos from the sources of cosmic-rays
Search for neutrinosfrom dark matterannihilations
Search for neutrinos from cosmological events
NewPhysics
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 sources1:1:1 after oscillations
Observing Neutrinos
IceCube
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IceTop air shower array80 pairs of ice Cherenkov tanks
IceCube (deep ice)80 strings of 60 optical modules17 m between optical modules125 m between strings1 km3 (1 Gton) detector!
AMANDA19 strings, 677 OMs totalø 200m, height 500m
~1
0-20
m
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
νμμ
X X’
W
detection principle
energy deposited in OM
time recorded on OM
Optical module
νe,τ
N X
W
e,τ
νμ,e,τ
N X
Z
νμ,e,τ
Charged-current interactions:
Neutral-current interactions:
e & detection principle
energy deposited in OM
time recorded on OM
Ice Properties• Ice not uniform in depth (e.g. dust layers)• Important to understand ice for analysis
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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
AMANDA
IceCube Today
500 m
Only IceToptank
InIce string& IceTop
• 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
“String 21” DataFirst IceCube string, deployed January 2005
Neutrino candidate9 string
Downgoing
IceCube event
AMANDA
QuickTime™ and aBMP decompressor
are needed to see this picture.
IceTop air shower array80 pair of ice Cherenkov tanks
IceCube (deep ice)80 strings of 60 optical modules17 m between optical modules125 m between strings1 km3 (1 Gton) detector!
AMANDA19 strings, 677 OMs totalø 200m, height 500m
“Diffuse Limits”• Measure the neutrino energy spectrum• Search for a break in the spectrum
Some AGN models excluded at 90% CL :Szabo-Protehoe 92
Stecker, Salamon. Space Sc. Rev. 75, 1996
Protehoe. ASP Conf series, 121, 1997E2μ
(E) < 2.6·10–7 GeV cm-2 sr-1 s-1
Results from one year (2000) of data
Consistent with Atmospheric neutrino expectation
Point Source SearchNeutrino sky map:
• 2000-2003 data: 807 days livetime• 3329 neutrino events• Largest significance = 3.4 (92% chance occurrence)• No significant excess observed
• 2000-2003 data: 807 days livetime• 3329 neutrino events• Largest significance = 3.4 (92% chance occurrence)• No significant excess observed
Neutrinos from GRBs
10 min -1 hour+1 hour
1.4501.29312 (BT)B-10/A-II97-00
1.8800.6046 (New)A-II2000
1.4701.24114 (All)A-II2000
2000
2000
1999
1998
1997
Year
A-II
A-II(2 analyses)
B-10
B-10
B-10
Detector
2.1900.2424 (BNT)
1.72/2.050/00.83/0.4044 (BT)
2.2400.2096 (BT)
2.2400.2094 (BT)
2.4100.0678 (BT)
Event U.L.NObsNBG, PredNBursts
Using space and time coincidence leads to a very low background.
No observed signal
Only ~1 order of magnitude above Waxmann&Bahcall prediction
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 (+…)
Earth
Detector
Freese, ’86; Krauss, Srednicki & Wilczek, ’86 Gaisser, Steigman & Tilav, ’86
Silk, Olive and Srednicki, ’85Gaisser, Steigman & Tilav, ’86
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…