Energy Reconstruction Algorithms for the ANTARES Neutrino Telescope
The ANTARES Neutrino Telescope A status report
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CEA DSM Irfu The ANTARES Neutrino Telescope A status report Niccolò Cottini on behalf of the ANTARES Collaboration 44 th Rencontres de Moriond February 2009
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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. - PowerPoint PPT Presentation
Transcript of The ANTARES Neutrino Telescope A status report
CEA DSM Irfu
The ANTARES Neutrino TelescopeA status report
Niccolò Cottinion behalf of the ANTARES Collaboration
44th Rencontres de Moriond February 2009
05 / 02 / 2009 Niccolò Cottini 2CEA DSM Irfu
The ANTARES Collaboration
• Since 1996• 7 countries• 22 laboratories• 200 physicists,
engineers, sea scientists
05 / 02 / 2009 Niccolò Cottini 3CEA DSM Irfu
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
05 / 02 / 2009 Niccolò Cottini 4CEA DSM Irfu
The Neutrino Astronomy
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Neutrino astronomy
p
Galaxy
Local galaxy group
p/A + p/ +0+
e e
• : interact with CMB and matter
• Protons: deflection by magnetic fields
• : weakly interacting
– huge target needed (100Mton - Gton)
05 / 02 / 2009 Niccolò Cottini 6CEA DSM Irfu
Potential sources
GALACTIC
Supernova remnants
Pulsars
Microquasars
EXTRAGALACTIC
GRBs
AGNs
Indirect dark matter search
See Damien Dornic’s talk
See Vincent Bertin’s talk
05 / 02 / 2009 Niccolò Cottini 7CEA DSM Irfu
Detection principle
43°
interaction
Sea floor
Cherenkov light from
3D PMTarray
Main detection channel: charged interaction giving an ultrarelativistic
Energy threshold: 10 GeV
ANTARES 12 lines MC
05 / 02 / 2009 Niccolò Cottini 8CEA DSM Irfu
The ANTARES detector
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The ANTARES site
• 42°50’ latitude Nord• 6°10’ longitude Est
• Galactic Center– visible 75% of the day
Galactic coordinates
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Toulon
La Seyne
Submarine cable (~40km)
Shore Station
The ANTARES site
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The ANTARES detector
~60 m
100 m
350 m
14.5 m
Link cable
JunctionBox
Cable toshore
2500m depth
05 / 02 / 2009 Niccolò Cottini 12CEA DSM Irfu
The ANTARES detector
Storey
45°
05 / 02 / 2009 Niccolò Cottini 13CEA DSM Irfu
Hydrophone
17’’ glass sphere10’’ PMT
A detector storey
DAQSlow Control
Titanium frame
LED Beacon
~10 cm resolution
~0.6 ns resolution
05 / 02 / 2009 Niccolò Cottini 14CEA DSM Irfu
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
05 / 02 / 2009 Niccolò Cottini 15CEA DSM Irfu
Detector layout
See Kay Graf’s talk
Acoustic storey
… and several instruments for environment studies with the ANTARES infrastructure
05 / 02 / 2009 Niccolò Cottini 16CEA DSM Irfu
Detector operations
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The detected signal
• Muon (Cherenkov)– 2 µs crossing time
• 40K decay– Continuous background
30 kHz *
• Bioluminescence– Continuous background
30 kHz *– Occasional bursts ~MHz
Simulation
2 min
* 10’’ PMT, 0.3 p.e. threshold
792 days
05 / 02 / 2009 Niccolò Cottini 18CEA DSM Irfu
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
atmospheric
Atmosphere
Sea
Earth
cosmic
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Muon flux at the detector
Atmosphere
Earth
Sea
107 atmospheric per year*103 atmospheric
per year*
cosmic
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
* Reconstructed tracks in 12 line detector
05 / 02 / 2009 Niccolò Cottini 24CEA DSM Irfu
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
data
CORSIKA (QGSJET01) + NSU model
MC uncert.
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Selection of neutrino events with 5 lines
Upgoing events dominated by the tail of badly reconstructed atmospheric muons
Upgoing events Downgoing events
Data, MC, MC (x100)
Likelihood ratio
: maximum likelihood of the track fit
MC
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Data, MC, MC (x100)
Selection of neutrino events with 5 lines
Purity = ~90%; Efficiency = ~30%
y = s(x) / [ s(x) + b(x) ]
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Detection of atmospheric neutrinos with 5 lines
)()(4)(41218 342 syststattheor
Data : 185 (1,1 / j), 93% purity
ANTARES 5 lines (164 days live time)
MC :
• Test of detector response to a known neutrino signal
• A preliminary step before searching for cosmic sources
Bartol flux (20% uncertainty on the absolute flux)
Mainly optical module response and calibration uncertainties (preliminary)
DataMCUncertainties
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Search for point like neutrino sources with 5 lines
See Katia Fratini’s talk
No discovery 90% CL flux limit
• Definition of a potential source list
• Analysis optimization by MC, for E-2 flux
• Data unblinding: 94 neutrino events
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Preliminary analysis of 10 line data
208 neutrinos
Preliminary quality cuts
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 and , cosmic neutrino sources, dark matter
• Neutrino oscillations, magnetic monopoles, VHE neutrino interactions, …
• On the road for the next step
– KM3Net…
KM3See Christopher Naumann’s talk
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Vue de la salle de contrôle d’ANTARESA view from ANTARES control room
