The ANTARES Neutrino Telescope A status report

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The ANTARES Neutrino TelescopeA status report

• Niccolò Cottini
• on behalf of the ANTARES Collaboration

44th Rencontres de Moriond February 2009
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The ANTARES Collaboration

• Since 1996
• 7 countries
• 22 laboratories
• 200 physicists, engineers, sea scientists

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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

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The Neutrino Astronomy
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Neutrino astronomy
?
?
p

• g interact with CMB and matter
• Protons deflection by magnetic fields
• n weakly interacting
• huge target needed (100Mton - Gton)

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Potential sources
GALACTIC
EXTRAGALACTIC
Indirect dark matter search
GRBs
Supernova remnants
See Damien Dornics talk
See Vincent Bertins talk
Pulsars
AGNs
Microquasars
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Detection principle
Main detection channel charged nm interaction
giving an ultrarelativistic m Energy threshold
10 GeV
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The ANTARES detector
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The ANTARES site

• 4250 latitude Nord
• 610 longitude Est

• Galactic Center
• visible 75 of the day

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The ANTARES site
Toulon
La Seyne
Submarine cable (40km)
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The ANTARES detector
2500m depth
Cable to shore
Junction Box
Link cable
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The ANTARES detector
Storey
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A detector storey
LED Beacon
DAQSlow Control
0.6 ns resolution
17 glass sphere 10 PMT
Titanium frame
Hydrophone
10 cm resolution
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2006 2008 deployments of the detector lines
60 m

• Line 1 03 / 2006
• Line 2, 3, 4, 5 01 / 2007
• Line 6, 7, 8, 9, 10 12 / 2007
• Line 11, 12 05 / 2008

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Detector layout
Acoustic storey
See Kay Grafs talk
and several instruments for environment studies
with the ANTARES infrastructure
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Detector operations
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The detected signal

• Muon (Cherenkov)
• 2 µs crossing time
• 40K decay
• Continuous background ? 30 kHz

Simulation
2 min

• Bioluminescence
• Continuous background ? 30 kHz
• Occasional bursts MHz

792 days
10 PMT, 0.3 p.e. threshold
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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
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Track reconstruction
?35o
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Number of triggers
10 or more lines (2008)
5 lines (2007)
Data taking ongoing
accumulating neutrinos
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The first physics analyses
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atmospheric n
atmospheric m
cosmic n
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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
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Atmospheric muon studies with 5 lines

• Systematic uncertainty 30
• Main contributions
• optical module response
• absorption length of the light in water

See Claire Picqs talk
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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
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Selection of neutrino events with 5 lines
Data, m MC, n MC (x100)
y s(x) / s(x) b(x)
Purity 90 Efficiency 30
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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)
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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 Fratinis talk
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Preliminary analysis of 10 line data
Preliminary quality cuts
208 neutrinos
Dec 2007 Apr 2008 100 days live time
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A neutrino event on 12 lines
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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 Naumanns talk
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Vue de la salle de contrôle dANTARES
A view from ANTARES control room