Recent Results from the ANTARES experiment

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


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


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


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.


The ANTARES site

Electro-opticalCable of

40 km

Institut M. Pacha


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


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


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


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


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


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

Time D

epth


5-lines data (2007)

2007 data - 19 •106 triggers

Total: 245 days

Selected: 168 days


Total: 245 days

Selected: 168 days

Down Up Detected event are mainly due to downgoing atmospheric muons


5-lines data (2007)


Total: 245 days

Selected: 168 days


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


candidate events


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


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


Selected sources for 2007 point source search


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



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


Point source search - ResultsUpper limits (90% c.l.), as a function of the declination, for

the selected point-like sources.

arXiv:0909.1262v1


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


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


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


• MC error band (theoretical + systematic) 30%




Down Up

Single & multi-line fit events are shown.


2007-2008 data

2007 (5 lines) :

168 d. 19 •106 triggers

2008 ( 9 lines):

173 d. 65 •106 triggers


2007 (5 lines) :

168 d. 19 •106 triggers

2008 ( 9 lines):

173 d. 65 •106 triggers


All 2007/2008 silver runs ~ 1000 s



All 2007/2008 silver runs ~ 1000 s



Down Up candidate events


2007-2008 skymap750 multilines neutrino candidates from 2007 and 2008, for 341 days of detector lifetime.

ANTARES 2007-2008 skymap (scrambled data)


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


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.......


Backup slides


2007 data

Observed: 185 events

MC: 2184(stat)41(theor) +3-42

(syst)


MC: 2184(stat)41(theor) +3-42

(syst)

Results of 2 independent analysis






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:


Expected performance

Effective areaNdet=Aeff × Time × Flux


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.

Recent Results from the ANTARES experiment

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