Status of ANTARES: An Undersea Neutrino Telescope Paschal COYLE, Centre de Physique des Particules de Marseille School and Workshop on Neutrino Particle Astrophysics Les Houches, 21-31 Jan 2002
Scientific Motivation Scientific Motivation Low Energy Medium Energy High Energy (10 GeV < E ν < 100 GeV) (10 GeV < E ν < 1 TeV) (E ν > 1 TeV) neutralino search ν from galactic and extra- ν oscillations (signal from annihilating galactic sources (x-ray (observation of first WIMPs in the Earth, binaries, SNR, AGN, oscillation minimum the Sun and the Galaxy) from atmospheric ν ) GRB) +Oceanography - measurements of oceanographic parameters of deep sea - studies of bioluminescence 2
ANTARES Timeline ANTARES Timeline “Demonstrator” “Demonstrator” Collaboration formed Collaboration formed line deployment line deployment and operation and operation Site evaluation programme Site evaluation programme to select a suitable site to select a suitable site Deployment of lines 1 to 10 Deployment of lines 1 to 10 Sector Line deployment Sector Line deployment Sector Line mechanical test Sector Line mechanical test 2 detector 0.1km 2 detector 0.1km EO Cable deployed and tested EO Cable deployed and tested complete complete Technical design report completed Technical design report completed 3
ANTARES Collaboration � NIKHEF, Amsterdam � University of Sheffield � ITEP, Moscou � IFIC, Valencia � CPPM, Marseille � DSM/DAPNIA/CEA, Saclay � C.O.M. Marseille � Universitat, Erlangen � University of Bari � IFREMER, Toulon/Brest � University of Bologna � LAM, Marseille � University of Catania � IReS, Strasbourg � LNS – Catania � Univ. de H.-A., Mulhouse � University of Rome � ISITV, Toulon � University of Genova 4 � Observatoire de la Côte d’Azur
Water Transparency Water Transparency λ abs ~ 55-65 m ; λ scat > 100 m at large angles 5
Biofouling Optical Backgrounds Optical Backgrounds Biofouling ~ 60 kHz (10” PM) Short bursts (bioluminescence) over a continuous background ( 40 K). Bioluminescence rate-function of sea current For θ > 90º transmission loss ~5% of time a PMT is unusable < 1.5% in 1 yr (and saturates) 6
Demonstrator Line Demonstrator Line • Immersed: Nov. 99 - June 00 • Depth of 1100 m • 350 m line height, 16 storeys • 7 PMTs, prototype acoustic positioning system • Line controlled and readout via 37 km electro-optical cable, analog transmission (digital for 0.1 km 2 ) Real time sonar display Boat Line (descending) 7
Acoustic Positioning Prototype Prototype Acoustic Positioning 4 transponders 3 distancemeters 134.1 mesures interpolation 134.05 Y coord. Range 3 (m) 134 D3 (m) Precision ( σ ) distance 133.95 Y 133.9 Inter-distancemeter ~ 1 cm 5cm Inter-transponder ~ 1 cm 133.85 ≤ 3 cm Range-Transponder 133.8 0 10 20 30 40 50 60 70 80 90 Time (min) temps (min) Triangulation → ~5 cm final precision 8
µ events Reconstruction of atmospheric µ events Reconstruction of atmospheric � 50 000 events with 7-fold coincidences recorded � Depth vs. time pattern used to generate hyperbolic fit � 40 K hits filtered out by reconstruction software z(m) 40 K noise ct (m) 9
ANTARES Site ANTARES Site Antares Site 60Km SE Marseille Depth 2400m Shore Base La Seyne-sur-Mer 40 km Submarine cable -2400m 10
Installations in La Seyne sur Mer Installations in La Seyne sur Mer Detector Assembly Hall Foselev Marine Salle de contrôle Chambre de test La Seyne sur Mer Zone d’intégration Land Cable Stockage Préparation ( Fibre optics ) Power Hut Les Sablettes Submarine cable ( Fibre optics + power ) Shore Station Villa Michel Pacha 11
ANTARES 0.1km 2 detector • 10 lines 2400m • 30 storeys / line • 3 PMT / storey 40 km to shore 12 m 350 m 100 m Junction box 60 m Readout cables 12
A Detector Line A Detector Line Buoy Electro-mechanical Cable 6 sectors* - mechanical support 5 storeys - core with 21 optical fibres and power lines *3 PMs =90 PMs/line LED Beacon (one per sector) Optical Module (3 per storey) - 10” PMT, active base, LED calibration system 12 m Local Control Module: Electronics container - front end ASIC, “ARS”: time, amplitude - acoustic positioning - data acquisition: 5 storeys → sector ethernet 1Gb/s 100m String Control/Power Module: Electronics containers - string power supplies - data acquisition: 6 sectors → DWDM → 6x1Gb/s on 1 fibre Interlink cable, - wet-mateable connector: 4 optical fibres+ 2 power lines Bottom String Structure Sea bed - acoustic string release system 13
The Optical Module The Optical Module LED pulser Optical gel Photomultipler: 10 inch Hamamatsu Active PMT base (ISEG) Glass sphere (Nautillus) Mu metal magnetic shield 14
Expected Performance: Effective Area Effective Area Expected Performance: trigger reconstruction selection Geometrical surface 15
Expected Performance: Resolution Expected Performance: Resolution Energy Resolution Angular Resolution o o 10 TeV • 5 GeV < E < 100 GeV Energy estimated from µ range σ E ~ 3 GeV • E > 1 TeV σ E / E ~ 3 Includes all effects (TTS, positioning, scattering etc.,) except phase → group velocity of light 16
View of the Sky View of the Sky ANTARES (43° North) AMANDA (South Pole) Mkn 421 Mkn 421 Mkn 501 Mkn 501 ~Never seen RXJ 1713.7-39 SN1006 SN1006 RXJ 1713.7-39 CRAB CRAB Never seen CasA CasA PSR B1706-44 PSR B1706-44 VELA 1ES2344+514 1ES2344+514 VELA PKS 2155-30 PKS 2155-30 (Gamma ray flux >100 MeV observed by EGRET) • Sky coverage: 3.6 π sr EGRET Source Type number of sources seen by Antares seen by Amanda • overlap with AMANDA All 271 89% 43% Indicative, assumes AGN 94 86% 52 • Galactic Center surveyed efficiency=100% Pulsars 5 100% 40% for 2 π downwards Unidentified Gal. Plane 55 93% 36% Unidentified off Gal. Plane 116 90% 40% Need a Neutrino Télescope in both Northern and Southern Hemispheres 17
View of the Sky (microquasars) AMANDA (South Pole) ANTARES (43° North) GX339-4 (Gamma ray flux >100 MeV observed by EGRET) Source type number of sources seen by Antares Indicative, assumes efficiency=100% EGRET AGN 94 86% for 2 π downwards EGRET Pulsars 5 100% Known Microquasars 19 74% 18
Check of Pointing Calibration Using Moon Shadow Check of Pointing Calibration Using Moon Shadow Look for deficit of downgoing muons from moon direction Minimium observation (2 σ ) time 2 years Misalignment >0.5° ⇒ moon shadow not visible anymore Angular resolution degraded for downward going muons 19
Atmospheric Neutrino Oscillations Atmospheric Neutrino Oscillations Ideal Reconstruction P( µ→τ )= sin 2 2 θ sin 2 (1.27 ∆ m 2 L/E), ∆ m mass difference, θ mixing angle E energy of ν , L oscillation length ν ν ν ν Simulation, 0.1km 2 , 3 years ν ν ν ν ν L~D earth cos θ µ 20
Comparison with other Experiments Comparison with other Experiments - Bartol atmospheric ν flux Preliminary 90% CL - Normalization left free - 3 years data taking (~2000 evts) (2007) Statistical errors+ 5% bin-by-bin uncorrelated systematic (prel.) 21
Search for Neutralino Annihilation Search for Neutralino Annihilation χ Halo of Dark Matter: χ ρ χ ~ 0.3 GeV/ cm 3 , χ χ χ v χ ~270 km/sec χ χ χ χ χ χ χ χ χ χ χ χ χ χ χ χ WIMP looses energy by elastic interaction χ if V< V escape =>capture χ χ χ χ capture + annihilation balance => constant density in core W →µν µ χ b → c µν µ χ ~ χ + b χ χ b → c µν µ W →µν µ soft spectrum (tt if M χ >M top ) hard spectrum ( ττ if M χ <M W ) 22
Expected Muon Flux Limits for Sun Expected Muon Flux Limits for Sun • Apply standard selection • Add 3° pointing cut around calculated sun direction SUN Preliminary soft • Predicted backgrounds from hard 15 years atmospheric neutrinos: 1.7/year 6 years 4 years • The band is the range covered by the hard and soft spectra • Assumes no oscillations • Dedicated reconstruction will significantly improve the sensitivity in the low mass region 23
Predicted Neutrino Flux from the Sun Predicted Neutrino Flux from the Sun -mSUGRA scan using SUSPECT - fluxes from DARKSUSY log neutrino flux A 0 =0, µ >0, tan β =10 pure gaugino from sun (/km 2 /yr) excluded by Ω wimp h 2 >1 (related to neutralino and chargino masses) mixed gaugino Excluded by LEP and b → s gamma (related to squark masses) 24
Comparison with mSUGRA Models and Direct Detection Comparison with mSUGRA Models and Direct Detection mSUGRA Models considered: Gaugino fraction 1 year Soft 0.4-0.7 A 0 =0, µ >0, tan β =10, 0.7-0.95 Hard M 1/2 =0-800 GeV, M 0 =0-1000 GeV 0.95-1.0 + Ω wimp h 2 <1 +LEP constraints ⇒ region of theoretical interest The corresponding spin-independent DAMA cross-section per nucleon for these Gaugino fraction CDMS 0.4-0.7 models compared to direct detection 0.7-0.95 limits ⇒ Very competitive! 0.95-1.0 Other SUSY models under study 25
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