Neutrino telescopes in the Mediterranean sea Marco Anghinolfi INFN-Genova on behalf of the ANTARES Collaboration HEP2012 Vlaparaiso, January 2012 The ANTARES detector Results and physics analisys in ANTARES

The goals Amsterdam - 30 March 2011 Th. Stolarczyk - CEA Irfu 2 p/A + p /             HE  HE    HE  HE     e e  e e e +  HE  e +  e +  HE  (inverse Compton) Pulsars Supernova remnants AGN Microquasars GRB Origin of cosmic rays Understanding of know sources Unknown phenomena Galactic Extra- Galactic

Detection Principle Neutrinos (E > 100GeV)can be detected using the visible Cherenkov radiation produced as the high-energy charged leptons (final state of CC interactions) propagate through a transparent medium with superluminal velocity.

p  ~10 3 atm.  p,  10 7 atm.  per year     cosm. Signal to noise

The sky coverage of ANTARES 42°50’ North 6°10’ East 2500 m depth

The ANTARES detector

A typical up-going event How does a muon look like?

EnvironmentalBackground

Reconstructed up-going events/day Neutrinos (multi-line, single-line) per day single line multi line Period with high bioluminescence full 12 line connection

5-line data (May-Dec. 2007) line data (2008) reconstruction BBfit v3r2, single- and multi-line fit elevation angle  down-going up-going good agreement with Monte Carlo: atmospheric neutrinos: 916 (30% syst. error) atmospheric muons: 40 (50% syst. error) 1062  cand. Comparison to Monte Carlo

11 Well reconstructed Badly reconstructed uncertainties in angle reconstruction: median: 0.5 O 12-line data: 0.4 O absolute orientation:  0.1 O data set: data taken with 5, 9, 10, and 12 operating detector lines Search for point-like sources

Full-sky search 12 Most significant cluster at: RA = ‒ 46.5°, δ= ‒ 65.0° N sig = 5 Q = p-value = Significance = 2.2 σ Sky map in Galactic Coordinates Background colour indicates visibility Result compatible with the background hypothesis Blue points: 3058 selected events Red stars: candidate source list

Best Limits for the Southern sky Assuming an E -2 flux for a possible signal ANTARES days × 2.5 improvement w.r.t. previous analysis (304 days) For most of the sources ANTARES gives the most stringent limits. (IceCube requires very high energy component (E >1 PeV) for Southern Sky).

Rencontres de Moriond 2011 M. Vecchi Search for a diffuse cosmic flux Idea: Background atmospheric neutrinos have a steeply falling energy spectrum: N ~E -3.5 Many cosmic neutrino model predict much harder spectra, typically N ~E -2 → Look for high– energy diffuse flux component Analysis: Live time: 334 days ( ) Stringent selection: 134 high energy candidates, no atmospheric  ’s Energy estimator R: a measure of the number of delayed photons High energy muons can produce more than one hit in the same PMT

Results on diffuse cosmic flux

On-going Physics analyses  flux from Fermi bubbles

Fermi bubbles Two scenarios: Su et al.: bubbles due to highly relativistic electrons emitting sincrotron radiation (GHz-WMAP) and simultaneously produce inverse-Compton  rays. M.Crocker & F.Aharonian: bubbles due to hadronic process : CR protons associated with long timescale star formation in the GC and injected in the bubbles by star wind  HE neutrinos

Fermi bubbles If the hadronic scenario is confirmed FB are possible HE neutrino sources for telescopes in the Mediteranean sea. Very extended source: same analysis of diffuse neutrino flux. Need to discriminate according to energy. Analysis just started: expected flux limits soon

Searches for Neutrinos from GRB Triggered search method: Dedicated low level trigger after a gamma-ray satellite alert (GCN) Requires Satellite trigger Low backgrounds due to direction and time coincidences

Search for muons produced by neutrinos in correlation with gamma-ray : candidate tracks are required to point back to the GRB position to within 2° and to occur during the arrival of prompt photons. 37 GRBs in the analysis applied to the data taken during the alerts occurred in No neutrino candidate muons were observed in correlation with the GRBs. The limits placed on the average flux of these bursts at the 90% confidence level, for three different GRB models A second search uses an alternative method to identify the shower at the neutrino-interaction vertex. This search is particularly sensitive to electron-neutrinos. 90% CL Upper limits on nu fluxes from 37 GRBs Searches for Neutrinos from GRB

21 Transient sources: Flares Motivation: Fermi data shows a extremely variable HE universe Main goal: Selects flares from Fermi catalog & look for coincidences: strong correlation between the gamma-ray and the neutrino fluxes is expected Method: adapt the un-binned method used in the point-like source by adding a time PDF Data: FERMI: started July 2008 => used the data taken with the full 12 lines ANTARES detector during the last four months of Gamma-ray light curve of the blazar 3C454.3 measured by Fermi above 100 MeV for almost 2 years of data

Transient sources: Flares Selection: sources located in the visible part of the sky by Antares from which the averaged one day-binned flux in the high state is greater than photons.cm -2 s -1 above 300 MeV. Most significant event: one neutrino event has been detected in time/space coincidence with the gamma-ray emission from the flare 3C279 p-value of about 10 %, still compatible with background fluctuations Perspectives: the most recent measurements of Fermi in show very large flares yielding to a promising search of neutrinos Gamma-ray light curve of the blazar 3C279. The red bar is the time of the ANTARES neutrino event

ANTARES & AUGER ultra high energy cosmic rays are expected to be accompanied by gamma-rays and neutrinos from pion decays field of view for the ANTARES telescope and the Pierre Auger Observatory (PAO) greatly overlap. correlation of arrival directions of 2190 neutrino candidate events detected by 5-12 line ANTARES neutrino telescope, and 69 UHECRs observed by the PAO

ANTARES & AUGER The most probable count for the optimized bin size of 5.2° is events in all 69 bins with standard deviation of events. After unblinding 2190 Antares neutrino candidate events, a count of 315 events within 69 bins is obtained  NO CORRELATION found Circles: 5.2 ° bins centered on UHECRs observed by AUGER. Black triangles: ANTARES neutrino events correlating with observed UHECRs (inside bin) Pink crosses : ANTARES neutrino events outside the bins

Multi-Messenger astronomy Strategy: higher discovery potential by observing different probes Higher significance by coincidence detection Higher efficiency by relaxed cuts GCN GRB Coord. Network: γ satellites Alerts Ligo/Virgo Gravitational waves: trigger + dedicated analysis chain TAROT optical follow up: 10 s repositioning MoUs for joint research

An exemple: optical follow-up Alerts sent by ANTARES High energy (n hits & amp) expected ~ 2/month TAROT: 2 telescopes Diameter: 25 cm Field of view: 1.86°×1.86° Magnitude limit:18-19 (within 1-3 min image acq.) ROTSE: 4 robotic telescopes: Diameter: 45 cm Field of view: 1.85°×1.85° Magnitude limit: ~19 for 1 minute exposure 27 alerts sent in 2 years ( ) 17 followed 9not followed 1 cancelled Image to analyze Reference Image Subtraction Image analysis under development

Supra-luminal neutrinos Cohen-Glashow idea: In case of Lorentz invariance violation, some processes are kinematically allowed (A. Cohen, S. Glashow, New Constraints on Neutrino Velocities, arXiv: v1) Test: take the highest energy events and put limits on  OPERA  

Supra-luminal neutrinos The mesurement : Assume neutrino production in the atmosphere, look for most enegetic upgoing muons, take the muon energy as the neutrino threshold energy Ethr take the distance L as the neutrino path in the Earth, The data: Maximum estimated energy  40 TeV L=cos  x D Earth =5340 Km Results in   Considering energy reconstruction uncertainty, a conservative upper limit is set to  ≥ 1.7 x10 -10

… and more Nuclearites & monupoles Close to unblinding data. Good prospects for limits. Neutrinos from galactic plane Will start soon Indirect dark matter searches Analysis from the Sun started CR composition Hit clustering algorithm selection in progress Supernova detection Tough due to bioluminescence. But double and triple coincidence method have sensitivity up to 4-5 kpc provided background rate is low Detection of HE γ-rays In progress. Cosmic rays anisotropies Just started

… not only neutrino detection The 13th line is used for the calibration of the neutrino telescope but also contains several instruments dedicated to marine and Earth sciences and to acoustic detection This facility allows the continuous monitoring of the most important characteristics of the sea water at the site of the detector The data are essential for a comparison to the models which describe the deep sea waters behaviour in the Mediterranean and to the R&D for future neutrino acoustic detection

CONCLUSIONS ANTARES today: Successful end of construction phase Technology proven Data taking ongoing First physics outputs: set limits on Point like neutrino sources, Diffuse neutrino flux …..On the road for the next step: a detector at the km3 scale in the Mediterranean sea Analysis in pogess on: Neutrino flux from FB Coincidences with GRB and high energy flares Neutrino oscillations, magnetic monopoles, Indirect dark matter search etc.