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The ANTARES Neutrino Telescope A status report. Niccol ò Cottini on behalf of the ANTARES Collaboration. 44 th Rencontres de Moriond February 2009. The ANTARES Collaboration. Since 1996 7 countries 22 laboratories 200 physicists, engineers, sea scientists. Outline of the talk.
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The ANTARES Neutrino TelescopeA status report Niccolò Cottini on behalf of the ANTARES Collaboration 44th Rencontres de Moriond February 2009
The ANTARES Collaboration • Since 1996 • 7 countries • 22 laboratories • 200 physicists, engineers, sea scientists Niccolò Cottini
Outline of the talk • Neutrino astronomy • The potential sources • The ANTARES detector • Construction milestones • Detector operations • The data taking campaign • The first physics analyses • Atmospheric muons • Atmospheric neutrinos • Search for cosmic neutrino sources • Indirect dark matter detection Niccolò Cottini
The Neutrino Astronomy Niccolò Cottini
Local galaxy group Galaxy p/A+p/g p+ p0+ ... g g nmm nm nee Neutrino astronomy • g: interact with CMB and matter • Protons: deflection by magnetic fields • n: weakly interacting • huge target needed (100Mton - Gton) p Niccolò Cottini
Potential sources GALACTIC EXTRAGALACTIC Indirect dark matter search GRBs Supernova remnants See Damien Dornic’s talk See Vincent Bertin’s talk Pulsars AGNs Microquasars Niccolò Cottini
ANTARES 12 lines MC 3D PMTarray Cherenkov light from m 43° Sea floor m nm interaction Detection principle Main detection channel: charged nm interaction giving an ultrarelativistic m Energy threshold: 10 GeV Niccolò Cottini
The ANTARES detector Niccolò Cottini
Galactic coordinates The ANTARES site 42°50’ latitude Nord 6°10’ longitude Est • Galactic Center • visible 75% of the day Niccolò Cottini
The ANTARES site Toulon Shore Station La Seyne Submarine cable (~40km) Niccolò Cottini
350 m 14.5 m 100 m ~60 m The ANTARES detector 2500m depth Cable to shore Junction Box Link cable Niccolò Cottini
The ANTARES detector 45° Storey Niccolò Cottini
A detector storey LED Beacon DAQSlow Control ~0.6 ns resolution 17’’ glass sphere 10’’ PMT Titanium frame Hydrophone ~10 cm resolution Niccolò Cottini
2006 – 2008: deployments of the detector lines Line 1: 03 / 2006 Line 2, 3, 4, 5: 01 / 2007 Line 6, 7, 8, 9, 10: 12 / 2007 Line 11, 12: 05 / 2008 ~60 m Niccolò Cottini
Detector layout Acoustic storey See Kay Graf’s talk … and several instruments for environment studies with the ANTARES infrastructure Niccolò Cottini
Detector operations Niccolò Cottini
Muon (Cherenkov) 2 µs crossing time 40K decay Continuous background 30 kHz * The detected signal Simulation 2 min • Bioluminescence • Continuous background 30 kHz * • Occasional bursts ~MHz 792 days * 10’’ PMT, 0.3 p.e. threshold Niccolò Cottini
m The Trigger • Front end chip digitizes charge and time of a light signal • All data transmitted through multiplexed Gigabit links • the whole data flow can not be written to disk • Computer farm running a software trigger: • look in all directions for light signals compatible with a muon track • when found, write a Physics Event • Other triggers exist: cluster of storeys, GRBs, Galactic Center, … “ALL DATA TO SHORE” SCHEME: Niccolò Cottini
Track reconstruction =35o Niccolò Cottini
Number of triggers 5 lines (2007) 10 or more lines (2008) Data taking ongoing… …accumulating neutrinos Niccolò Cottini
The first physics analyses Niccolò Cottini
Atmosphere Sea Earth atmospheric n atmospheric m cosmic n Niccolò Cottini
Muon flux at the detector 107 atmospheric m per year* 103 atmospheric n per year* Atmosphere Sea Earth cosmic n * Reconstructed tracks in 12 line detector Line 1: 03 / 2006 Line 2, 3, 4, 5: 01 / 2007 Line 6, 7, 8, 9, 10: 12 / 2007 Line 11, 12: 05 / 2008 Performance paper submitted First physics analyses completed Ongoing analysis Data taking Niccolò Cottini
data CORSIKA (QGSJET01) + NSU model MC uncert. Atmospheric muon studies with 5 lines • Systematic uncertainty ± 30% • Main contributions • optical module response • absorption length of the light in water See Claire Picq’s talk Niccolò Cottini
Likelihood ratio Data, m MC, n MC (x100) Selection of neutrino events with 5 lines L: maximum likelihood of the track fit MC Upgoing events Downgoing events Upgoing events dominated by the tail of badly reconstructed atmospheric muons Niccolò Cottini
m n Selection of neutrino events with 5 lines Data, m MC, n MC (x100) y = s(x) / [ s(x) + b(x) ] Purity = ~90%; Efficiency = ~30% Niccolò Cottini
Data MC Uncertainties Detection of atmospheric neutrinos with 5 lines • Test of detector response to a known neutrino signal • A preliminary step before searching for cosmic sources ANTARES 5 lines (164 days live time) Data : 185 n (1,1 / j), 93% purity Mainly optical module response and calibration uncertainties (preliminary) MC : Bartol flux (20% uncertainty on the absolute n flux) Niccolò Cottini
Search for point like neutrino sources with 5 lines • Definition of a potential source list • Analysis optimization by MC, for E-2 flux • Data unblinding: 94 neutrino events No discovery 90% CL flux limit See Katia Fratini’s talk Niccolò Cottini
Preliminary analysis of 10 line data Preliminary quality cuts 208 neutrinos Dec 2007 – Apr 2008 : 100 days live time Niccolò Cottini
A neutrino event on 12 lines Niccolò Cottini
KM3 Conclusion • ANTARES today • Successful end of construction phase • Technology proven • Data taking ongoing • First physics outputs • Atmospheric m and n, cosmic neutrino sources, dark matter • Neutrino oscillations, magnetic monopoles, VHE neutrino interactions, … • On the road for the next step • KM3Net… See Christopher Naumann’s talk Niccolò Cottini
Vue de la salle de contrôle d’ANTARES A view from ANTARES control room Niccolò Cottini