Recent Results from the ANTARES experiment
Recent Results from the ANTARES experiment
Manuela Vecchi on behalf of the ANTARES
CollaborationUniversity of Roma “La Sapienza”
and INFNICATPP09- Como: October 6th 2009
Manuela Vecchi Como, October 6th 09 2
Outline
-astronomy: what, where, how and why?• The ANTARES detector...
– Detection technique– Antares facts & figures– Detector operation
• First Physics Analysis– Point Source Search– Transient Source Search– Indirect Dark Matter Search
• Multimessenger approach• Conclusions
Manuela Vecchi Como, October 6th 09 3
Neutrino Astronomy
Protons and photons are absorbed or deflected since they interact with matter/radiation.
Neutrinos can travel unscattered opening a new window on the far Universe.
• Electrically neutral not bent by the magnetic fields
• Interacts very slightly escape from the dense areas of the Universe
• No absorption observation at cosmological distances
• Only weakly interacting particles low interaction cross section large detection volume is required
quasar
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Detection principleNeutrinos can interact in the medium surrounding the telescope.
They can be detected using the visible Cerenkov radiation produced as the high-energy charged lepton passes through the transparent medium.
42°
interaction
Sea bed
Cherenkov light from
3D PMTarray
A deep underwater/ice detector is required to reduce the number of atmospheric
μs.
ANTARES 12 lines MC
Manuela Vecchi Como, October 6th 09 5
Detection principle
42°
interaction
Sea bed
Cherenkov light from
3D PMTarray
A deep underwater/ice detector is required to reduce the number of atmospheric
μs.
Our GOALs:
Search for production sites of HE neutrinos
Understand production mechanisms of HE neutrinos
Search for Dark Matter (WIMPs)
Exotic particles....
Our GOALs:
Search for production sites of HE neutrinos
Understand production mechanisms of HE neutrinos
Search for Dark Matter (WIMPs)
Exotic particles....
Neutrinos can interact in the medium surrounding the telescope. They can be detected using the visible Cerenkov radiation produced as the high-energy charged lepton passes through the transparent medium.
Manuela Vecchi Como, October 6th 09 6
The ANTARES site
Electro-opticalCable of
40 km
Institut M. Pacha
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The ANTARES detector
14.5 m
~60-75 m
Buoy
350 m
100 mJunction
box
Electro-optical Cable
Floor
• 12 Lines• 25 storeys / line• 3 PMTs / storey• 885 PMTs
Depth : 2475 m
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Detector Milestones
MILOM: 17th Mar 2005Line 1: 2nd Mar 2006Line 2: 21st Sep 2006Line 3, 4, 5: 29th Jan 2007Line 6, 7, 8, 9, 10: 7th Dec
2007Line 11, 12: 30th May 2008
~60 m
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Optical Background40K Decay Continuous 30kHz backgroundBioluminescence 30kHz background, MHz
outbursts…
40K
e4020
4019 eCaK
Counting rate for 2 PMTs on line 1, as a function of timeCounting rate for 2 PMTs on line 1, as a function of time
Manuela Vecchi Como, October 6th 09 10
Muon flux at the detectorThe data sample is dominated by the flux of atmospheric muons
propa- gating downward through the detector. Atmospheric neutrinos contribute providing a flux that is 4-5 orders of magnitude less abundant than that of atmospheric muons.
Atmosphere
Earth
Sea
108 atmospheric per year*103 atmospheric
per year*
cosmic
* Reconstructed tracks in 12 line detector
Manuela Vecchi Como, October 6th 09 11
Track reconstructionTrack reconstructed as upgoing through the detector, as
seen in the online event display. Each box correnspond to 1 detection line.
a rX
iv:0
9 08.
0816
v 1
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Track reconstructionTrack reconstructed as upgoing through the detector, as seen in the
online event display. Each box correnspond to 1 detection line.
a rX
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9 08.
0816
v 1
Time D
epth
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5-lines data (2007)
2007 data - 19 •106 triggers
Total: 245 days
Selected: 168 days
2007 data - 19 •106 triggers
Total: 245 days
Selected: 168 days
Down Up Detected event are mainly due to downgoing atmospheric muons
Manuela Vecchi Como, October 6th 09 14
5-lines data (2007)
2007 data - 19 •106 triggers
Total: 245 days
Selected: 168 days
2007 data - 19 •106 triggers
Total: 245 days
Selected: 168 days
Down Up
Neutrino candidate events:
Data: 168 observed
MC: 1643(stat)33(theor) 16 (syst)
Neutrino candidate events:
Data: 168 observed
MC: 1643(stat)33(theor) 16 (syst)
candidate events
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Atmospheric muons studies
dataCORSIKA (QGSJET01) + NSU modelMC uncert.
Systematic uncertainty due to uncertainties in the primary CR
flux and hadronic models.No quality cut (QC) applied.
CORSIKA (QGSJET01) + NSU modelCORSIKA (QGSJET01)+ Horandel model
MUPAGEdata
5 lines data
Azimuth angle distribution
dataCORSIKA (QGSJET01) + NSU modelMC uncert.
Zenith Angle Distribution
Manuela Vecchi Como, October 6th 09 16
Point source search - 2007data• Stringent cuts to ensure low background and
good resolution. • Search applied to 25 selected sources. • All-sky search has also been performed.
• Blinding policy followed
Two independent statistical methods used: BINNED and UNBINNED
Two independent statistical methods used: BINNED and UNBINNED
Selected sources for 2007 point source search
Manuela Vecchi Como, October 6th 09 17
Point source search - 2007data• Stringent cuts to ensure low background
and good resolution. • Search applied to 25 selected sources. • All-sky search has also been performed.• Blinding policy followed
Two independent statistical methods used: BINNED and UNBINNED
Two independent statistical methods used: BINNED and UNBINNED
Selected sources for 2007 point source search
5 line data - 94 candidate neutrino events selected in 168 active days. No significant excess has
been found.
ANTARES 2007 skymap
arXiv:0909.1262v1
Manuela Vecchi Como, October 6th 09 18
Point source search - ResultsUpper limits (90% c.l.), as a function of the declination, for
the selected point-like sources.
arXiv:0909.1262v1
Manuela Vecchi Como, October 6th 09 19
Search for transient sources
The response time of the satellite triggered data taking in Antares to a satellite alert message.
The response time of the satellite triggered data taking in Antares to a satellite alert message.
The satellite triggered data taking efficiency during all alert message broadcasts from the GCN
Search for candidates in correlation with GRB alerts from satellites.
Whenever an alert is received, a dedicated data-taking is performed.
arX
iv:0
908.
0818
v1
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Indirect dark matter searchCold Dark Matter Candidate: decays of neutralinos (WIMPs) gravitationally trapped in massive objects, i.e. the Sun, can produce HE s detectable by ANTARES.
Data sample 68.4 effective daysNo discovery 90% C.l. Upper limit
mSugra model predictionsgreen : WMAP favoured relic densityred : > WMAP favoured relic densityblue : < WMAP favoured relic density
A search for s from neutralino annihilation in the Sun has been performed on 2007 data.
A search for s from neutralino annihilation in the Sun has been performed on 2007 data.
arXiv:0905.2316v3
Manuela Vecchi Como, October 6th 09 21
2007-2008 data
2007 (5 lines) :
168 d. 19 •106 triggers
2008 ( 9 lines):
173 d. 65 •106 triggers
TOTAL 341 days lifetime.
2007 (5 lines) :
168 d. 19 •106 triggers
2008 ( 9 lines):
173 d. 65 •106 triggers
TOTAL 341 days lifetime.
• MC error band (theoretical + systematic) 30%
• MC error band (theoretical + systematic) 50%
• MC error band (theoretical + systematic) 30%
• MC error band (theoretical + systematic) 50%
Down Up
Single & multi-line fit events are shown.
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2007-2008 data
2007 (5 lines) :
168 d. 19 •106 triggers
2008 ( 9 lines):
173 d. 65 •106 triggers
TOTAL 341 days lifetime.
2007 (5 lines) :
168 d. 19 •106 triggers
2008 ( 9 lines):
173 d. 65 •106 triggers
TOTAL 341 days lifetime.
All 2007/2008 silver runs ~ 1000 s
• MC error band (theoretical + systematic) 30%
• MC error band (theoretical + systematic) 50%
All 2007/2008 silver runs ~ 1000 s
• MC error band (theoretical + systematic) 30%
• MC error band (theoretical + systematic) 50%
Down Up candidate events
Manuela Vecchi Como, October 6th 09 23
2007-2008 skymap750 multilines neutrino candidates from 2007 and 2008, for 341 days of detector lifetime.
ANTARES 2007-2008 skymap (scrambled data)
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Multimessenger approach
* Télescopes à Action Rapide pour les Objets Transitoires
Agreement with TAROT*:• optical telescope at
La Silla (CL)• FOV: 1.86° x 1.86°• Fast (~10s) re-positioning• Optical follow-up of
transient sources triggered by the ANTARES detectorThe trigger is satisfied when: 1 evt with E > few TeV or 2 evts detected within = 3°
x 3°.
Joint searches between gravitational-wave interferometers and ANTARES.
•Possible common sources (GRBs from core-collapse SN or from BH/NS binary merger; SGR; powerful magnetars; hidden sources)
• Sky regions in common
• Expected low signals, coincidences increase chances of detection
www.gwhen-2009.org
arXiv:0908.0804v2
arXiv:0908.2454v1
Manuela Vecchi Como, October 6th 09 25
Conclusions
• The ANTARES experiment is complete and taking data.
• First analyses on 2007 data show that the detector perfomance is well within expectactions.
• First upper limits to the flux of neutrinos from point-like sources have been set.
• First flux limits from ‘hard’ and ‘soft’ neutralino annihilation in the Sun have been set.
• Analysis of 2008 data is under way.• Multimessenger approach is strongly pursued.
…detected 1000 neutrino candidates, a lot more science to come.......
Manuela Vecchi Como, October 6th 09 26
Backup slides
Manuela Vecchi Como, October 6th 09 27
2007 data
Observed: 185 events
MC: 2184(stat)41(theor) +3-42
(syst)
Observed: 185 events
MC: 2184(stat)41(theor) +3-42
(syst)
Results of 2 independent analysis
Observed: 168 events
MC: 1643(stat)33(theor) 16 (syst)
Observed: 168 events
MC: 1643(stat)33(theor) 16 (syst)
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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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Expected performance
Effective areaNdet=Aeff × Time × Flux
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Indirect DM search (2)ANTARES 2007 data Upper limit to the flux of + anti
from neutralino annihilation in the Sun, compared to other experiments, as a function of neutralino mass.
ANTARES FULL DETECTORPredicted measured flux of + anti
from neutralino annihilation in the Sun, for the full ANTARES detector, after 5 years.
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