vrije universiteit brussel, belgium
DESCRIPTION
6 th Cracow Epiphany Conference. http://amanda.uci.edu. http://icecube.wisc.edu. The AMANDA – IceCube telescopes & Dark Matter searches. B. Baret on behalf of the IceCube collaboration. Vrije Universiteit Brussel, Belgium. [email protected]. Physics Motivations and Goals. AMANDA. - PowerPoint PPT PresentationTRANSCRIPT
B.Baret Vrije Univertsiteit Brussel
Vrije Universiteit Brussel, Belgium
The AMANDA – IceCube telescopes&
Dark Matter searches
B. Baret on behalf of the IceCube collaboration
http://amanda.uci.edu http://icecube.wisc.edu
6th Cracow Epiphany Conference
B.Baret Vrije Univertsiteit Brussel
Physics Motivations and Goals
AMANDA
IceCube
Attractive astronomical messengers:•Transparent Universe (≠)•Travel in straight line (≠p)•Produced in hadronic accelerators ?
Study of:Sources:
AGNs, SNRs, GRBs...-physics (atmospheric
production):Oscillations, cross-sections..
“new” physics:WIMPS, decoherence, monopoles...
B.Baret Vrije Univertsiteit Brussel
The IceCube collaborationUSA: Bartol Research Institute, Delaware Univ. of Alabama Pennsylvania State University UC Berkeley UC Irvine Clark-Atlanta University Univ. of Maryland IAS, Princeton University of Wisconsin-Madison University of Wisconsin-River Falls LBNL, Berkeley University of Kansas Southern University and A&M
College, Baton Rouge
Sweden: Uppsala Universitet Stockholm Universitet
UK: Imperial College, London Oxford University
Netherlands: Utrecht University
Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut
Germany: Universität Mainz DESY-Zeuthen Universität Dortmund Universität Wuppertal Humboldt Universität, Berlin
Japan: Chiba University
New Zealand: University of Canterbury
B.Baret Vrije Univertsiteit Brussel
Where are we ?
Amundsen-Scott South Pole Station
Here! (South pole)
IceCube
Amanda
North
Technically North also
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Detection principle
O(km) long tracks
O(10m) cascades e,
South Pole Ice properties (@400nm):
Scattering:~20m Pointing res. (~2° , casc. ~35°)
Absorption:~110m Effective volume
Background (x E.T. events/year):atmospheric O(109)atmospheric O(103)
E.T. atm.
p
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Layout
IceCube:
1km x1 km² instrumented volume
4800 Digital Optical Modules (DOMs) on 80 strings
IceTop(air shower array):
1km² instrumented area
160 surface water tanks with 2 DOMs each
Amanda:Ø=200m, h=500m (0.02 km³)Amanda B-10:
302 Optical Modules (OMs) on 10 strings (97-99)
Amanda II:677 OMs on 19 strings (00->)
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IceCube Deployment
January 2005:First string deployed60 DOMs installed (and working!)
Hot water drilling:2450 m deepstraight within 1m35-40 hrs per hole
Deployment:2 more strings up to nowExpected completion in 2010
B.Baret Vrije Univertsiteit Brussel
IceCube First Events!
IceTop – IceCube
String 21
Down going IceTop tanks
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all-flavor limitsνμ (B10 1yr)
νμ (A-II 4yr)
νμ (A-II 1yr) νe+νμ+ντ (cascades A-II 1yr)
νe+νμ+ντ (UHE B10 1yr)
νe (cascades B10 1yr)
νe+νμ+ντ (UHE A-II 1yr)
Sensitivity and limits
Icecube (1yr)
WB bound
Limit
Sensitivity
Diffuse search
ave
rag
e fl
ux
up
per
lim
it [
cm-2s-1
]
sin
AMANDA-B10
AMANDA-II
IceCube 1/2 year
*
Steady point sources sensitivity:
E-2 flux hypothesis
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Point sources
Sky map (00'-03')
Significance maps
No point source detected so far...
3329
real sky
scrambled skyno source
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Neutralino as dark matter candidate
Cosmological observationsm ~ 0.30
b ~ 0.05
Minimal Supersymmetric Standard ModelPR conserved LSP stable = neutralino
interacts weakly = GeV-TeV mass = dark matter??? stable
dark, non-baryonic matter
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Neutralino capture by Sun and Earth
Sun – direct capture from galactic DM halo
Earth – capture by gravitational diffusion and weak scattering
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Which WIMP signal
Neutralino-induced neutrinos
l+l-
W, Z, H
Atmospheric background
atm. : absorbed by the Earth
atm. : compare on/off source
angular regions
“down”
“up”
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Data and Monte Carlo used
Data1997-1999: 5.0x109 events 536.6 days eff. livetime2001: 8.7x108 events 143.7 days eff. livetime
Monte Carloneutralino: 50 GeV < M < 5000 GeV[DARKSUSY] hard (W+W-) and soft (bb) ann. channel
90° < < 113° (Sun) ~ 180° (Earth)
atm. : Sun: 32 days Earth: 128 days[CORSIKA] 600 GeV < Ep < 1011 GeV 0° < p < 90°
atm. : Sun: 2.104 evts Earth: 2.108 evts [ NUSIM ] 10 GeV < E < 108 GeV 80° < < 180°
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Rejection of signal & background
Earth 1997-1999 (paper in preparation)
Sun 2001 (submitted to Astrop. Phys.)
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No excess of neutralino-induced neutrinos
signal region
signal region
Earth 1997-1999 (paper in preparation)
Sun 2001 (submitted to Astrop. Phys.)
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Muon flux limits – Earth ’97-’99
Improvements (wrt. ’97)separate filter for each neutralino model
more statistics
Outlook2001-2003 data set
improved reconstructions
new trigger lowers Ethresh
PA
PE
R IN
P
RE
PA
RA
TIO
N
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Muon flux limits - Sun 2001
1st AMANDA solar neutralino results200m diameter enables robust reconstruction of horizontal tracks
Outlook2000-2003 data setimproved reconstructions
new trigger lowers Ethresh
AMANDA results submitted for publication
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Conclusion & outlook
AMANDA & IceCube:Amanda
provided very useful information (ice, drilling, detection strategy, bkgd, ...)
providing tighter and tighter constraints on models
IceCubeall flavour detection, ~30x more sensitive almost guaranteed discoveries
Is being deployed and takes data
WIMPs search:No statistically significant excess of neutralino-induced neutrinos from the center of the Earth or the Sun observed
Upper limits on the muon flux competitive with other indirect searches
Additional data are being analysed with improved techniques
B.Baret Vrije Univertsiteit Brussel
B.Baret Vrije Univertsiteit Brussel
Technically
Optical Module
Digital Optical Module
Trigger, Digitization, HV
Surface DOM
time res. <2ns400ns and 6.4µs range3 gainsnoise ~700Hz
time res. ~4-8 ns32 µs rangenoise: ~1kHz
Digitized Waveform
8” PMT
10” PMT+Main Board+flasher
Amanda IceCube
single p.e.
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Plan...
Season planning:
Nov.: preparationDec.: constructionJan.: constructionFeb.: commissioning
Deploymentof string N
Drilling of hole N
0h 12h 24h 36h 48h 60h 72h 84h
Time
This austral summer : 8 to 12 strings deployed
By 2010 : 1km³ instrumented