Transcript
Page 1: Juande Zornoza  (IFIC, Valencia) on behalf  of  the  ANTARES  collaboration

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

Page 2: Juande Zornoza  (IFIC, Valencia) on behalf  of  the  ANTARES  collaboration

*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

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*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

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*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

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*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

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*Data vs MC: elevation

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*Data vs MC: fit quality

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*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)

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• 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

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MWIMP = 350 GeV

*Main annihilation channels

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*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)

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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

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Muon flux sensitivity for ANTARES 2007-2008Preliminary

Flux Φμ

Annihilation rate Γ

Capture rate C

Cross-section σSD

*Muon flux sensitivity

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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

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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

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*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…

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* Neutrino candidate with 12-line detector

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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