Download
slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Neutrino telescopes in the Mediterranean sea PowerPoint Presentation
Download Presentation
Neutrino telescopes in the Mediterranean sea

Neutrino telescopes in the Mediterranean sea

105 Views Download Presentation
Download Presentation

Neutrino telescopes in the Mediterranean sea

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

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

  2. The goals Extra-Galactic Galactic GRB Supernova remnants e+ ge +gHE(inverse Compton) p/A +p/g p0 + p + ...  gHEgHEnmm  nm nee Pulsars Microquasars AGN • Origin of cosmic rays • Understanding of know sources • Unknown phenomena Th. Stolarczyk - CEA Irfu

  3. 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.

  4. p,  107 atm. per year  ~103 atm.  p   cosm.  Signal to noise

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

  6. The ANTARES detector

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

  8. EnvironmentalBackground

  9. Reconstructed up-going events/day full 12 line connection Periodwithhigh bioluminescence single line multi line Neutrinos (multi-line, single-line) per day

  10. Comparison to Monte Carlo 5-line data (May-Dec. 2007)+ 9-12 line data (2008) reconstruction BBfit v3r2, single- and multi-line fit down-going up-going 1062  cand. elevation angle  good agreement with Monte Carlo: atmospheric neutrinos: 916 (30% syst. error) atmospheric muons: 40 (50% syst. error)

  11. Search for point-like n sources Badly reconstructed Well reconstructed data set: 2007-2008 data taken with 5, 9, 10, and 12 operating detector lines uncertainties in angle reconstruction: median: 0.5O 12-line data: 0.4O absolute orientation: 0.1O

  12. Full-sky search Sky map in Galactic Coordinates Background colour indicates visibility Blue points: 3058 selected events Red stars: candidate source list Most significant cluster at: RA= ‒46.5°, δ= ‒65.0° Nsig = 5 Q = 13.02 p-value = 0.026 Significance = 2.2 σ Result compatible with the background hypothesis

  13. Best Limits for the Southern sky Assuming an E-2 flux for a possible signal ANTARES 2007-2010 813 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).

  14. 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 (2007-2009) • Stringent selection: 134 high energy n candidates, no atmospheric m’s • Energy estimator R: a measure of the number of delayed photons • Highenergymuons can produce more thanone hit in thesame PMT M. Vecchi

  15. Results on diffuse cosmic  flux

  16. On-going Physics analyses n flux from Fermi bubbles

  17. Fermi bubbles Two scenarios: • Su et al.: bubbles due to highly relativistic electrons emitting sincrotron radiation (GHz-WMAP) and simultaneously produce inverse-Compton g 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

  18. 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

  19. 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

  20. Searches for Neutrinos from GRB • 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 2007. • 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

  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 2008. Gamma-ray light curve of the blazar 3C454.3 measured by Fermi above 100 MeV for almost 2 years of data

  22. 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 20 10-8 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 2009-11 • show very large flares yielding to a • promisingsearch of neutrinos Gamma-ray light curve of the blazar 3C279. The red bar is the time of the ANTARES neutrino event

  23. 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

  24. ANTARES & AUGER 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 The most probable count for the optimized bin size of 5.2° is 343.34 events in all 69 bins with standard deviation of 15.69 events. After unblinding 2190 Antares neutrino candidate events, a count of 315 events within 69 bins is obtained NO CORRELATION found

  25. Multi-Messenger astronomy Strategy:higherdiscoverypotentialby observingdifferentprobes Highersignificanceby coincidencedetection Higherefficiencyby relaxedcuts MoUs for joint research Alerts TAROT optical follow up: 10 s repositioning Ligo/Virgo Gravitationalwaves: trigger + dedicated analysischain GCN GRB Coord. Network: γ satellites

  26. An exemple: opticalfollow-up • Alerts sent by ANTARES • High energy  (nhits& amp) • expected ~ 2/month • 27 alerts sent in 2 years (2009-2010) • 17 followed • 9 not followed • 1 cancelled • 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 Image analysis under development Image to analyze Reference Image Subtraction

  27. 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:1109.6562v1) • Test: • take the highest energy events and put limits on d • OPERA : d10-5

  28. Supra-luminal neutrinos • Themesurement: • Assume neutrino production in theatmosphere, • look formostenegeticupgoingmuons, • takethe muon energy as the neutrino thresholdenergyEthr • takethedistance L as the neutrino path in theEarth , • The data: • Maximumestimatedenergy 40 TeV • L=cosq x DEarth=5340 Km • Results in d 4 10-11 • Consideringenergyreconstructionuncertainty, • a conservativeupperlimitis set to • d≥ 1.7 x10-10

  29. … and more • Nuclearites & monupoles • Close to unblinding 2007-2008 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

  30. … 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

  31. 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 • Analysis in pogess on: • Neutrino flux from FB • Coincidences with GRB and high energy flares • Neutrino oscillations, magnetic monopoles, • Indirect dark matter search • etc. • …..On the road for the next step: • a detector at the km3 scale in the • Mediterranean sea