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Indirect search of Dark Matter with the ANTARES
Neutrino Telescope
Vincent Bertin - CPPM-Marseille on behalf of the
ANTARES Collaboration
MORIOND on Very High Energy Phenomena in the
Universe La Thuile - Feb 2009
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Indirect detection of WIMPs in a neutrino
telescope
Relic WIMPs captured in celestial bodies
m
n
n
c
c
c
c
n
c
n
n
cc self-annihilations into c,b,t quarks, t
leptons or W,Z,H bosonscan produce significant
high-energy neutrinos flux
Potential cc?n sources areSun, Earth Galactic
Centre
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Neutralino annihilations in the Sun in mSUGRA
Neutralino annihilations in the Sun in mSUGRA
Study of neutralino Dark Matter sensitivity
within SUSY mSUGRA framework
Integrated neutrino flux for En gt 10 GeV

• Random walk scan within mSUGRA parameter space
  0 lt m1/2 lt 2000 GeV 0 lt m0 lt 8000 GeV 0 lt tanb
  lt 60 -3 m0 lt A0 lt 3 m0
• Calculated with DarkSUSYand ISASUGRA (RGE code)
  with mtop 172.5 GeV
• Includes n oscillation effectsinside and outside
  the Sun

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Effective area of the ANTARES detector
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Low energy performance of the ANTARES detector
ANTARES Low-Energy Effective Area
Assume 60 kHz of optical background mean rate
Trigger Events with hits on at least 5 storeys
in whole detectorDetection Selected after 3D
reconstruction with quality cuts( cf talk
Niccolo Cottini )
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Neutrino spectra from neutralino annihilations
Neutrinos from cc ? WW (hard spectrum) are more
energetic and easier to detect
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Neutralino annihilations in the Sun in mSUGRA
Neutralino annihilations in the Sun in mSUGRA
Detection rate with ANTARES and KM3NeT detectors
Sensitivity calculated for3 years of taking data
Background from atmospheric neutrinos and
misreconstructed atmospheric muons within 3
radius search cone around the Sun
KM3NeT detector cf talk Ch. Naumann
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Neutralino annihilations in the Sun in mSUGRA
Medium tanb regime
mSugra Parameter Space
Focus Point Region
High tanb regime
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Search for neutralino annihilations in the Sun
Exclusion capabilities of ANTARES for the mSUGRA
parameter space
Excludable in 3 years at 90 CL all some none
(A0 varied between -3m0 and 3m0 and tan(ß)
within indicated slice)
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Search for neutralino annihilations in the Sun
Exclusion capabilities of KM3NeT for the mSUGRA
parameter space
Excludable in 3 years at 90 CL all some none
(A0 varied between -3m0 and 3m0 and tan(ß)
within indicated slice)
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Muon flux from neutralino annihilations in the Sun
Muon flux from the Sun in mSUGRA
Used for comparison to other neutrino
experiments Site dependent quantity(n
propagation through Earth, target density at
detector) Derived from neutrino flux through n
? µ conversion rate extracted from DarkSUSY for
different m?
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Comparison to Direct Detection sensitivity
Comparison to direct detection experiments
sensitive to spin independent WIMP-nucleon cross
section Spin dependent scattering limits not yet
low enough to put constraints on mSUGRA Dark
Matter CDMS arXiv0802.3530 XENON
arXiv0706.0039
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Analysis of the ANTARES 5-line data sample
200 reconstructed neutrinos events in 167 days
of effective lifetime (cf talk Niccolo Cottini)
Azimuth Angle Distribution Detector acceptance
not uniform due to line distribution on sea floor
Zenith Angle Distribution upgoing events only
Data MC possible MC systematic errors from
alignment resolution, uncertainty of PMT
angular acceptance and efficiency, charge
calibration
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Search for neutrino events coming from the Sun
Expected sensitivity and background in a cone
around the Sunfor the ANTARES 5-line upgoing
neutrino sample
Good agreement for background estimation from MC
and full sky data set Size of search cone
optimized on MC as a function of Mc and
hard/soft spectrum
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First ANTARES limit on n/m flux from the Sun
Promising limit based ondata with ½ of ANTARES
detector within 6 months
Limit with b-quark (soft) or W-boson (hard)
annihilation channel
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Summary and Outlook

• ANTARES detector is working well first search
  on Dark Matter annihilation in the Sun performed
  on 5-line data
• Interesting signal of SUSY Dark Matter for
  neutrino telescopes
• Part of mSUGRA parameter space accessible to
  ANTARESin 3 years (Focus Point Region)
• Most of Focus Point Region can be explore by
  KM3NeT detector
• Complementarity of neutrino telescopes with
  direct detectionand LHC
• Sensitivity to other SUSY models (pMSSM, AMSB,)
  orDark Matter candidates is being studied (KK
  excitations,)
• Search towards Galactic Centre and Earth in
  progress
• More than 1000 neutrinos already collected !

Lets find the Dark Matter for the next Moriond !!
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BACKUP SLIDES
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Neutrino telescope Detection principle
3D PMTarray
p, a
nm
p
m
Cherenkov light from m
gc
nm
g
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Sea floor
m
interaction
Reconstruction of m trajectory ( n) from timing
and position of PMT hits
n
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The ANTARES detector

• 900 PMTs
• 12 lines
• 25 storeys / line
• 3 PMTs / storey

40 km to shore
Junction Box
Interlink cables
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The ANTARES Collaboration

• NIKHEF, Amsterdam
• KVI Groningen
• NIOZ Texel

• ITEP,Moscow

• University of Erlangen

• ISS, Bucarest

• IFIC, Valencia
• UPV, Valencia

• CPPM, Marseille
• DSM/IRFU/CEA, Saclay
• APC Paris
• IPHC (IReS), Strasbourg
• Univ. de H.-A., Mulhouse
• IFREMER, Toulon/Brest
• C.O.M. Marseille
• LAM, Marseille
• GeoAzur Villefranche

• University/INFN of Bari
• University/INFN of Bologna
• University/INFN of Catania
• LNS Catania
• University/INFN of Pisa
• University/INFN of Rome
• University/INFN of Genova

M. Circella Status of ANTARES
VLVnT08
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ANTARES Collaboration
ANTARES Collaboration detector site
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ANTARES Construction Milestones

• 2001 2003
• Main Electro-optical cable in 2001
• Junction Box in 2002
• Prototype Sector Line (PSL) Mini
  Instrumentation Line (MIL) in 2003

• 2005 2006
• Mini Instrumentation Line with OMs (MILOM)
  running since April 2005
• Line 1 running since March 2006,first complete
  detector line
• Line 2 running since September 2006

• 2007 2008
• Line 3-5 running since Jan 2007
• Line 6-10IL07 since Dec 2007
• Line 11-12 since May 2008
• 2008 Physics with full detector !

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Expected performance (MC Studies)

• Angular resolution better than 0.3 above a few
  TeV, limited by
• Light scattering chromatic dispersion in sea
  water s 1.0 ns
• TTS in photomultipliers s 1.3 ns
• Electronics time calibration s lt 0.5 ns
• OM position reconstruction s lt 10 cm (? s lt 0.5
  ns)

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Region of sky observable by Neutrino Telescopes
ANTARES (43 North)
AMANDA (South Pole)
Mkn 421
Mkn 501
Mkn 501
RX J1713.7-39
GX339-4
Galactic Centre
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Detector response to power law flux
Detector response function for neutrino
flux E?
events /?E
? 105
2 Tev -1 Pev
Log10 (E? /GeV)
Neutrino Telescopes naturally much more sensitive
to high energies
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Muon reconstruction

• On shore data filtering
• Local trigger L1 coincidence lt 20 ns on storey
• At least 4 L1 in coincidence ?  Physics event 
• A single line ? poor sensitivity to azimut ? use
  4 parameters chi2 fit

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Data taking with 12 line complete detector !
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Reconstruction of atmospheric muon tracks
Reconstruction with Line1 Algorithm minimizes ?2
of PMT hit time vs. altitude to find zenith
angle of m track

• Online Data filter
• Look for local coincidences (trigger hits)
  within 20ns
• Ask for 5 trigger hits

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Backgrounds
µ
?
p
?
p
Quality cuts required to remove atmospheric muon
background
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MC Study of detector down going muons
Water absorption length
OM angular acceptance
Different parameterisations
10 variation
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Estimation of systematic errors
Work in progress present situation
Typically systematics for upward going neutrinos
½ downward going muons
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Reconstructed events with 5 line data
Data June 2007 Dec 2007 139 active days
Multi line fit
Single line fit
98 neutrinos
54 neutrinos
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Reconstructed events with 10 line data
Data Dec 2007 May 2008 109 active days
Multi line fit
Single line fit
224 neutrinos
88 neutrinos
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KM3NeT

• ANTARES,NEMO and NESTOR work together to build
  km3-large detector in the Mediterranean
• Project on ESFRI Roadmap
• Conceptual Design Report approved
• Technical Design Report in preparation
• Detector proposal providing Aeff
• 225 lines in grid configuration
• 36 Optical Modules per line
• 21 PMTs (3) per OM

artist impression
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Event rate in search cone around the Sun

• RED
• of observed events inside the search cone
  around the Sun
• BLUE - SOLID
• of background events inside the search cone
  around the Sun, where the background sample was
  estimated by scrambling the direction and the
  time of all observed events
• BLUE - DASHED
• of background events inside the search cone
  around the Sun, where the background corresponds
  to the total atmosph. ?µ ?µ flux (Honda
  parameterisation) during data taking
• BLACK SOLID
• Upper limit _at_ 90 C.L. on the of signal events
  inside the search cone around the Sun, assuming
  Poissonian statistics according to the
  Feldman-Cousins unified approach
• BLACK DASHED
• Expected upper limit (or sensitivity) _at_ 90
  C.L. on the of signal events inside the search
  cone around the Sun, assuming Poissonian
  statistics according to the Feldman-Cousins
  unified approach