Recent Results from the ANTARES experiment Manuela Vecchi

Recent Results from the ANTARES experiment Manuela Vecchi on behalf of the ANTARES Collaboration University of Roma “La Sapienza” and INFN ICATPP 09 - Como: October 6 th 2009 Como, October 6 th 09 Manuela Vecchi

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 Como, October 6 th 09 Manuela Vecchi 2

Neutrino Astronomy quasar 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 Como, October 6 th 09 Manuela Vecchi 3

Detection principle Neutrinos can interact in the medium surrounding the telescope. They can be detected using the visible C erenkov radiation produced as the high-energy charged lepton passes through the transparent medium. ANTARES 12 lines MC 3 D PMT array Cherenkov light from 42° Sea bed Como, October 6 th 09 interaction Manuela Vecchi A deep underwater/ice detector is required to reduce the number of atmospheric μs. 4

Detection principle Neutrinos can interact in the medium surrounding the telescope. They can be detected using the visible C erenkov radiation produced as the high-energy charged lepton passes through the transparent medium. Our GOALs: 3 D PMT array X Search for production sites of HE neutrinos XUnderstand production mechanisms of HE neutrinos Cherenkov light from XSearch for Dark Matter (WIMPs) 42° XExotic particles. . Sea bed Como, October 6 th 09 interaction Manuela Vecchi A deep underwater/ice detector is required to reduce the number of atmospheric μs. 5

The ANTARES site Institut M. Pacha Electro-optical Cable of 40 km Como, October 6 th 09 Manuela Vecchi 6

The ANTARES detector • 12 Lines • 25 storeys / line • 3 PMTs / storey • 885 PMTs Buoy Floor 14. 5 m 350 m 100 m Junction box Electrooptical Cable ~60 -75 m Depth : 2475 m Como, October 6 th 09 Manuela Vecchi 7

Detector Milestones ~60 m MILOM: 17 th Mar 2005 Line 1: 2 nd Mar 2006 Line 2: 21 st Sep 2006 Line 3, 4, 5: 29 th Jan 2007 Line 6, 7, 8, 9, 10: 7 th Dec 2007 Line 11, 12: 30 th May 2008 Como, October 6 th 09 Manuela Vecchi 8

Optical Background 40 K Decay Continuous 30 k. Hz background Bioluminescence 30 k. Hz background, MHz outbursts… 40 K Counting rate for 2 PMTs on line 1, as a function of time Como, October 6 th 09 Manuela Vecchi 9

Muon flux at the detector The 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. 103 atmospheric per year* 108 atmospheric per year* Atmosphere Sea Earth cosmic * Reconstructed tracks in 12 line detector Como, October 6 th 09 Manuela Vecchi 10

Track reconstruction ar. Xiv: 0908. 0816 v 1 Track reconstructed as upgoing through the detector, as seen in the online event display. Each box correnspond to 1 detection line. Como, October 6 th 09 Manuela Vecchi 11

Track reconstruction Depth Track reconstructed as upgoing through the detector, as seen in the online event display. Each box correnspond to 1 detection line. Como, October 6 th 09 Manuela Vecchi ar. Xiv: 0908. 0816 v 1 Time 12

5 -lines data (2007) 2007 data - 19 • 106 triggers Total: 245 days Selected: 168 days Up Como, October 6 th 09 Down Manuela Vecchi Detected event are mainly due to downgoing atmospheric muons 13

5 -lines data (2007) candidate events Neutrino candidate events: Data: 168 observed MC: 164 3(stat) 33(theor) 16 (syst) 2007 data - 19 • 106 triggers Total: 245 days Selected: 168 days Up Como, October 6 th 09 Down Manuela Vecchi 14

Atmospheric muons studies Azimuth angle distribution Zenith Angle Distribution data CORSIKA (QGSJET 01) + NSU model MC uncert. 5 lines data Systematic uncertainty due to uncertainties in the primary CR flux and hadronic models. No quality cut (QC) applied. Como, October 6 th 09 Manuela Vecchi data MUPAGE CORSIKA (QGSJET 01) + NSU model CORSIKA (QGSJET 01) + Horandel model 15

Point source search - 2007 data • 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 Como, October 6 th 09 Manuela Vecchi 16

Point source search - 2007 data • Stringent cuts to ensure low background and good resolution. • Search applied to 25 selected sources. • All-sky search has also been performed. ANTARES 2007 skymap • Blinding policy followed Two independent statistical methods used: BINNED and UNBINNED 5 line data - 94 candidate neutrino events selected in 168 active days. No significant excess has been Selected sources for 2007 point source search Como, October 6 th 09 Manuela Vecchi found. ar. Xiv: 0909. 1262 v 1 17

Point source search - Results Upper limits (90% c. l. ), as a function of the declination, for the selected point-like sources. ar. Xiv: 0909. 1262 v 1 Como, October 6 th 09 Manuela Vecchi 18

Search for candidates in correlation with GRB alerts from satellites. Whenever an alert is received, a dedicated data-taking is performed. Como, October 6 th 09 Manuela Vecchi The satellite triggered data taking efficiency during all alert message broadcasts from the GCN ar. Xiv: 0908. 0818 v 1 Search for transient sources The response time of the satellite triggered data taking in Antares to a satellite alert message. 19

Indirect dark matter search Cold Dark Matter Candidate: decays of neutralinos (WIMPs) gravitationally trapped in massive objects, i. e. the Sun, can produce HE s detectable by ANTARES. ar. Xiv: 0905. 2316 v 3 A search for s from neutralino annihilation in the Sun has been performed on 2007 data. Data sample 68. 4 effective days No discovery 90% C. l. Upper limit m. Sugra model predictions green : WMAP favoured relic density red : > WMAP favoured relic density blue : < WMAP favoured relic density Como, October 6 th 09 Manuela Vecchi 20

2007 -2008 data 2007 (5 lines) : 168 d. 19 • 106 triggers 2008 ( 9 lines): 173 d. 65 • 106 triggers TOTAL 341 days lifetime. Up Down Single & multi-line fit events are shown. • MC error band (theoretical + systematic) 30% • MC error band (theoretical + systematic) 50% Como, October 6 th 09 Manuela Vecchi 21

2007 -2008 data 2007 (5 lines) : 168 d. 19 • 106 triggers 2008 ( 9 lines): 173 d. 65 • 106 triggers TOTAL 341 days lifetime. Up Down candidate events All 2007/2008 silver runs ~ 1000 s • MC error band (theoretical + systematic) 30% • MC error band (theoretical + systematic) 50% Como, October 6 th 09 Manuela Vecchi 22

2007 -2008 skymap 750 multilines neutrino candidates from 2007 and 2008, for 341 days of detector lifetime. ANTARES 2007 -2008 skymap (scrambled data) Como, October 6 th 09 Manuela Vecchi 23

Multimessenger approach Agreement with TAROT*: • optical telescope at La Silla (CL) • FOV: 1. 86° x 1. 86° • Fast (~10 s) re-positioning • Optical follow-up of transient sources ar. Xiv: 0908. 0804 v 2 triggered by the ANTARES detector The trigger is satisfied when: 1 evt with E > few Te. V or 2 evts detected within = 3° x 3°. * Télescopes à Action Rapide pour les Objets Transitoires 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 www. gwhen-2009. org Como, October 6 th 09 ar. Xiv: 0908. 2454 v 1 • Expected low signals, coincidences increase chances of detection Manuela Vecchi 24

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. . . . Como, October 6 th 09 Manuela Vecchi 25

Backup slides Como, October 6 th 09 Manuela Vecchi 26

2007 data Results of 2 independent analysis Observed: 168 events Observed: 185 events MC: 164 3(stat) 33(theor) 16 (syst) MC: 218 4(stat) 41(theor) +3 -42 (syst) Como, October 6 th 09 Manuela Vecchi 27

The trigger Front end chip digitizes charge and time of a light signal “ALL DATA TO SHORE” SCHEME: 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, … Como, October 6 th 09 Manuela Vecchi 28

Expected performance Effective area Ndet=Aeff × Time × Flux Como, October 6 th 09 Manuela Vecchi 29

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. Como, October 6 th 09 ANTARES FULL DETECTOR Predicted measured flux of + anti from neutralino annihilation in the Sun, for the full ANTARES detector, after 5 years. Manuela Vecchi 30