Juande Zornoza (IFIC, Valencia) on behalf of the ANTARES collaboration * Search for Dark Matter in the Sun with the ANTARES Neutrino Telescope in the CMSSM and mUED frameworks
Feb 23, 2016
Juande Zornoza (IFIC, Valencia)on behalf of the ANTARES collaboration
* Search for Dark Matter in the Sun with the ANTARES Neutrino Telescope in the CMSSM and mUED frameworks
*Scientific scope
MeV GeV TeV PeV EeV
Astrophysical neutrinosDark matter (neutralinos, KK)
Oscillations
Supernovae
GZK
Limitation at high energies:Fast decreasing fluxes E-2, E-3
Limitation at low energies:-Short muon range-Low light yield-40K (in water)
Detector density
Detector size
Origin of cosmic rays Hadronic vs. leptonic signatures Nature of dark matter
*Detection of DM by NTs*WIMPs (neutralinos, KK particles) are among the most popular
explanations for dark matter*They would accumulate in massive objects like the Sun, the
Galactic Center, dwarf galaxies…*The products of such annihilations would yield “high energy”
neutrinos, which can be detected by neutrino telescopes*In the Sun a signal would be very clean (compared with gammas
from the GC, for instance) *Sun travel in the Galaxy makes it less sensitive to non-
uniformities
*Detection principle of optical Cherenkov detectors
The neutrino is detected by the Cherenkov light emitted by the muon produced in the CC interaction.
1.2 TeV muon traversing ANTARES
N X
W
*Data*ANTARES was completed in 2008*During 2007, 5 lines were already operative*This analysis uses data of 2007 (5 lines) and 2008 (9-10-12 lines)*About 1000 up-going neutrino candidates in the selected sample*Binned search
*Data vs MC: elevation
*Data vs MC: fit quality
*Background
All upward-going events from 2007-2008 data Example of Sun tracking in horizontal coordinates
• Background estimated from data (2007-2008 period, ~295 days)• Fast algorithm for muon track reconstruction (Astro. Phys. 34 (2011) 652-662)• Using the Sun visibility at the ANTARES location• Background from CR interactions in the Sun corona much lower (few percent of total)
• The WIMPSIM package (Blennow, Edsjö, Ohlsson, 03/2008) is used to generate events in the Sun in a model-independent way
• Great statistics: with 3×106 WIMPs annihilations • Capture rate and annihilations in equilibrium at
the Sun core • Annihilations in c,b and t quarks, leptons and
direct channels• Interactions taken into account in the Sun
medium• Three flavors oscillations, regeneration of
leptons in the Sun medium (Bahcall et al.)• Available parameters: WIMPs mass, oscillations
parameters... Earth
*Signal: WimpSim
MWIMP = 350 GeV
*Main annihilation channels
*Signal and cut optimization• Neutrino flux at the earth, from the Dark Matter coannihilation, are convoluated with the efficiency of the detector for a cuts parameter space (track fit quality cut Q,cone)
• Neutrino background from the scrambled data in the Sun direction is evaluated in the same space
• Minimize this quantity:
Acceptance to be estimated for different sets (tchi2,cone)Average upper limit (Feldman-Cousins)
Neutrino flux sensitivity for 2007-2008 dataPreliminary For CMSSM:
Branching ratios = 1(WW, bb, ττ)
For mUED: Theoretical branching ratios taken into account
Reason:High dependence of branching ratios over CMSSM parameter space
*Neutrino flux sensitivity
Muon flux sensitivity for ANTARES 2007-2008Preliminary
Flux Φμ
Annihilation rate Γ
Capture rate C
Cross-section σSD
*Muon flux sensitivity
PreliminarySpin-dependent cross-section flux sensitivity for
ANTARES 2007-2008
Compare SUSY predictions to
observables as sparticles masses,
collider observables, dark matter relic density, direct detection cross-
sections, …SuperBayes
(arXiv:1101.3296)
χ2
*CMSSM cross-section sensitivity
G. Lambard
Spin-dependent cross-section flux sensitivity for ANTARES 2007-2008 Preliminary
1σ2σ
Compare mUED predictions to
observables as KK masses, collider
observables, relic density, direct
detection cross-sections, …
SuperBayes modified version
(Physical Review D 83, 036008 (2011))
*mUED cross-section sensitivity
G. Lambard
*Summary• Dark matter is a major goal for neutrino telescopes (and
an important complement to direct detection experiments)
• Computed the detector efficiency for two common dark matter models (CMSSM, mUED)
• First analysis done by looking at Sun; other sources (GC, dwarf galaxies…) to be done
• Sensitivities for the CMSSM and mUED, in muon flux and SD cross-section calculated: almost ready for unblinding 2007-2008 data
• Analysis on 2007-2010 data in progress…
* Neutrino candidate with 12-line detector
18
De C. Hettlage et al., Astropart.Phys. 13 (2000) 45-50 Simple parameterization averaged on the oscillations
* Background in the Sun direction IICR and Solar atmosphere
It doesn’t represent more than 10-3 events per year in a 5 lines cofiguration (few events for a km3), 0.4% of the total atmospheric background…
νμ
• Interactions p-p give a production of neutrinos through the decay products