Guillaume Lambard - XLIIIrd Rencontre de Moriond – Cosmology 2008 - 15-22/03/2008 Guillaume...

Guillaume Lambard Guillaume Lambard - - XLIIIrd Rencontre de Moriond – Cosmology 2008 - 15-22/03/2008XLIIIrd Rencontre de Moriond – Cosmology 2008 - 15-22/03/2008

ANTARES neutrino telescope status andANTARES neutrino telescope status and indirect searches of Dark Matter indirect searches of Dark Matter

Guillaume LambardGuillaume Lambard

Centre de Physique des Particules de MarseilleCentre de Physique des Particules de MarseilleFranceFrance


Antares collaboration & locationAntares collaboration & location


The DetectorThe Detector

~2500 m

~40 km EOC Site/Seyne-sur-Mer

14.5 m

~350 minstrumented

~100 mJunction box

~70m

EMC

12 lines (900 PMTs)5 sectors/line5 storeys/sector3 PMTs/storey

storey

P ~ 250 barsSCM


A detection storeyA detection storey


Antares detection principleAntares detection principle

Charged current interactionµ

µ track

Čerenkov cone

42°

ROCK

WATER

FLOOR

Detector

Time local coincidences between OMs and Storeys -> Time hits distributions Vs Detection locations


Observable sky by Antares Observable sky by Antares at the latitude of ~43°at the latitude of ~43°

Galactic center position

ANTARES galactic coordinates skymap of visibility

-180° 180°

90°

-90°


Antares.com : Breaking newsAntares.com : Breaking news

March 2006 : First line connected

September 2006 : Line 2

January 2007 : Lines 3-5

December 2007 : 10 Lines on the site

~May 2008 : Whole detector


Physical expected performancesPhysical expected performances

Angular resolution < 0.3° (E>~TeV) limited by:

• TTS in photomultipliers : σ ~ 1.4 ns

• Time Calibration : σ ~ 0.6 ns

• Line positioning : σ < 10cm (σ < 0.5 ns)

• Scattering and chromatic dispersion : σ < 1.0 ns

E <~10TeV : kinematicE >~10TeV : the detector


Physical expected performancesPhysical expected performances

Earth opacity for E > 100 TeV

Increase with energy

For 12 lines

dlEN

AEffAeENEA

)()()(),(


Reconstruction resultsReconstruction results

Case of ten lines reconstruction for a down-going event:

ΘΘ = 124.0°= 124.0° Track projection Track projection

in phase space in phase space (z,t)(z,t)



Case of ten lines reconstruction for an up-going event:

= 51.9°= 51.9°


Reconstruction resultsReconstruction resultsHits distribution over zenith and azimuth angles

Azimuth angle detector

topology effect on the hits distribution

At 12 Lines, the detector will be symmetric and this effect should disappeared in part

Discrepancies MC/data

Work on the OMs acceptance in progress…



Reconstructed Quality factor :

)1(1.0)log(

SolutionsDOF

NN

L Quality cut dertermined after Quality cut dertermined after Monte-carlo studies to discritimate Monte-carlo studies to discritimate the real up-going events with the the real up-going events with the down-going and misreconstructed down-going and misreconstructed eventsevents

All eventsAll events

ReconstrutReconstruted up-going ed up-going eventsevents


Dark Matter search perspectivesDark Matter search perspectives

in the Sunin the Sun

WIMPWIMP

Accretion into the sunAccretion into the sun

Self-annihilationSelf-annihilation

ANTARESANTARES

EEνν M MWIMPsWIMPsSunSun


Dark Matter search perspectives Dark Matter search perspectives

in the Sunin the Sun

● WIMPs traking down into heavy bodies by elastic scaterring and gravitational accretion

● Self-annihilations into primary and secondary neutrinos

● Interaction neutrinos/matter into the source-body

● Neutrinos oscillations from the source to the Earth

● Neutrinos/Earth medium charged current interactions -> muons

● Effective Area, neutrinos flux and source visibility -> number of events

Dark Matter indirect detection side – independent-model:


Annihilation rate and channelsAnnihilation rate and channels

WIMPs lose energy through an elastic scaterring off nucleons into the Sun mediumEquilibrium for Capture rate = annihilation rate

α (1000 GeV / mB(1))-6 *tanh2(mB(1)

-13/4)Considered channels :➢ Primary neutrinos → , dN/dE = (1/M)², UED model➢ Secondary neutrinos (Bertone, Servant, Sigl) from

➢ → qq → +/- → → ee,

➢ heavy quarks decay (before Hadronization) : b, c, t

➢ leptons and doublet of higgs *

➢ And WW, ZZ for neutralinos(MSSM, mSugra, etc...)

➢ Muon flux:

(GeV-1.m-2.an-

1)Oscillation over 3 flavors from the Sun to the Earth


UED modelUED model

UED model(Universal Extra-Dimensions): Every fields of the Standard Model propagate into the extra-dimensions (conventional space-time + 1 space dimension with a compactification scale to R constraints by the accelerator experiments)

• Conservation of the Kaluza-Klein parity in effective 4-dim theory

• KK lightest state → Dark Matter candidate

LKPs (Lightest KK Particles), non-baryonic and neutral particles corresponds to the first KK-resonance level of the hypercharge boson B (1) where (Servant-Tait) :

self-annihilation channels :

B(1) B(1) ff, hh, , p, e+, e- ,


Expected muons from DM self-annihilation Expected muons from DM self-annihilation

Expected muons events from the BExpected muons events from the B(1)(1) self- self-annihilationsannihilations

400GeV<MLKP<1TeV

Relic density 0 = 0.3 GeV/cm3

vLKP~220 km.s-1

SD~10-6pb

Compared to the atmospheric background ~5 evts for 3° in cone aperture around the Sun

Sun visibility for Antares in zenith angleSun visibility for Antares in zenith angle

Upward going part

Anticipated atmospheric bkg neutrinos per sec.Anticipated atmospheric bkg neutrinos per sec.


PRELIMINAR

Y

(at 12 lines)

Sensitivity of Antares to neutrinos from the Sensitivity of Antares to neutrinos from the SunSun

In the mSugra assumptionsIn the mSugra assumptions

Updates for 5 & 10 lines configuration in progress…

Lower limit from the « soft channel » (->bb)

Upper limit from the « hard channel »(->WW)


•Detection of neutrinos from Dark Matter annihilations into the mini-spikes around Intermediate Mass Black Holes (IMBHs)

•Mini-spikes -> bright sources of neutrinos

•Mini-spikes from the reaction of DM mini-halos to the formation of IMBHs

•IMBHs model study MIMBHs~ 105 M๏

•Better sentivity and high energy resolution of ACTs(HESS, INTEGRAL, CANGAROO,…) can be used to discriminate mini-spikes from the ordinary Astrophysical sources. But the full surveys favored the sea neutrino telescopes(Antares & IceCube).

•The location of Antares and an effective area of 1km2 appears to be the best for the detection-> Good perpectives for KM3-net

Dark Matter annihilations in mini-spikesDark Matter annihilations in mini-spikes


Mini-spikes ramdom distribution in the milky wayMini-spikes ramdom distribution in the milky way

Equatorial coordinates skymap of IMBHs in one random realization (red diamonds) and 200 realizations (blue diamonds) with a great concentration around the Galactic Center (yellow circle)

Galactic center position

ANTARES galactic coordinates skymap of visibility


Prospects for detecting Dark Matter with neutrino telescopes inIntermediate Mass Black Holes scenarios – G. Bertone arXiv:astro-ph/0603148v2

Prospects from mini-spikes assumptionsProspects from mini-spikes assumptions


Through a precise time calibration and acoustic positioning of the lines, we are able to extract :

• a full sky map and potentials spikes positions into the neutrinos distribution with an integrated data taking time > 300 days (5 & 10 lines configurations take into account)

• put limits over the LSP, LKP, etc… Dark Matter candidates masses by Sun, GC correlations the events direction through blind and unblind strategies (interesting for signals at low statistics)

• Good perpectives from the IMBHs models and growths of mini-spikes around. But, difficulty to discriminate the neutrinos flux from Dark Matter self-annihilations to the classic Astrophysical events. Needed a crosscheck with the GRs data.

Conclusions & perspectivesConclusions & perspectives

Galactic coordinates skymap of 116 up-going events

PRELIMINARY


BACK UPBACK UP


Expected neutrino flux from the Expected neutrino flux from the SunSun

• Neutralino LSP in mSugra theory

• mSugra parameter space through: m0,m1/2,A0,tan(),sign()

All models studied

0,094 < Ωh² < 0,129 (WMAP 3yr constraint)

Ω h² < 0,094

All models studied

0,094 < Ωh² < 0,129 (WMAP 3yr constraint)

Better signal

Expected neutrinos flux from the sourceExpected neutrinos flux from the source Expected neutrinos eventsExpected neutrinos events


Coincidences rates through the 40K decay (40K 40Ca + e- + e):

Čerenkov photons Čerenkov photons produced by produced by relativistic relativistic electronselectrons

Coincidences between adjacent optical modules

Backup:In situBackup:In situ calibration quality calibration quality

40K 40Ca + e- 2γ

Integral under the peak ~ muon flux

Shape is sensitive to angular acceptance of optical modules andangular distribution of muon flux

Adjacent floor coincidences :


Backup:LED Beacons IlluminationsBackup:LED Beacons Illuminations

Events

Events

t ( ns)

t ( ns)

Examples and view of in situ calibration by the LED beacon system in the sea. The mean of these distributions centered around ~0 check the good quality of the time calibration before the deployment.


Backup : Background noise Backup : Background noise expected…expected…Muons distribution over zenith

angle


Backup : TriggerBackup : Trigger

Before to really reconstruct a muon track, there are five data processing levels from the data taking to the discovering of potential events:

• Level 0 (L0) : All hits

• Level 1 (L1) : local trigger search

• local coinciding hits in a time gate (~20 ns) on 2 PMTs of the same floor

• and/or all hits with charge > threshold param. (~2.5 p.e.)

• Level 2 (L2) : global trigger search

• Space-time relation between signals due to unscattered light from the same muon trajectory or bright point

• assuming: high relativitic muons, slowest possible speed c/n (n~1.35). For two hits, causality implies:

xc

nt

Δt : time between hits

Δx : diff. Between PMTs positions



• Level 2 (L2) :

• if the number of correlated hits > “minClusterSize” parameter(~4) Cluster

For example for a 3D Trigger:

Minimum number of hits in the cluster = 5

Minimum number of floors in the cluster = 5

Minimum charge of the largest hits in the

cluster = 0.3 p.e.

etc…

• Level 3 (L3) : merging of overlapping events

• each event contains a snapshot of all hits in a time window around the cluster

tmaxCausal ~ 2.2 μs

• All hits within causality condition added

• Level 4 (L4) : event building

• All raw hits collected in a snapshot and combined into “PhysicsEvent” with data of clusters



After, all processing levels used into different forms of triggers which look for:

• 1D : time correlated hits in a given direction (L0 data in input)

• 3D : time correlated hits from any directions (L1 data in input)

• MX : similar to 1D + one local coincidence (1 L1) to speed up the processing of L0 data

And the number of L0 or L1 levels for each trigger can vary…

At the end, the muon track reconstruction strategy can apply to the selected hits…


Backup : Reconstrustion StrategyBackup : Reconstrustion Strategy

• Step 1 : Linear prefit by χ²-minimization over local coincidences and integrated charge of hits

• step 2 : M-estimator minimization

Ai = charge, ri = time residual, fang = angular factor, K=0.05 (MC simulation)

• step 3 : Likelihood-maximization

A likelihood cut is preformed to discriminate the « real » up-going events compare to the down-going muon misreconstructed.


Backup : Neutrinos Effective AreaBackup : Neutrinos Effective Area

dlEN

AEffAeENEA

)(

)()(),(


Backup : Neutrinos cross sectionsBackup : Neutrinos cross sections

σσcc,cc, from CTEQ coll. Parton Distribution from CTEQ coll. Parton Distribution FunctionsFunctions


Backup : Reconstruction resultsBackup : Reconstruction resultsLast case with five Lines:


Backup : Reconstruction resultsBackup : Reconstruction resultsrun 25685, frame 81559

3D reco.

(A. Heijboer)


Backup : Energy reconstructionBackup : Energy reconstruction

Factor 2 or 3 at low energy (<(TeV))


Backup : Sun CaseBackup : Sun Case

• Systematical analysis of data through an angular cut (dominated by the angular resolution at low energy) and an common ON/OFF area method. The up-going neutrinos events extracting into a 2° cone around the Sun position

• Likelihood cut

• Sun position computation into the topocentric(zenith and azimuth angle) and geocentric(declination, right ascention) frames, and eventually the apparent diameter to improve the cone aperture-> Common SLALIB library through an Antares ROOT Kit analysis dedicated


Backup : Sun CaseBackup : Sun Case

Apparent diameter ~0.53°-> angular resolution still dominates

Possibility to evaluate an expected background spectrum in zenith angle from the atmospheric neutrinos interactions

Guillaume Lambard - XLIIIrd Rencontre de Moriond – Cosmology 2008 - 15-22/03/2008 Guillaume...

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