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The ANTARES Underwater Neutrino Telescope

The ANTARES Underwater Neutrino Telescope

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The ANTARES Underwater Neutrino Telescope

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  1. The ANTARES Underwater Neutrino Telescope C.W. James, ECAP, University of Erlangen, on behalf of the ANTARES collaboration.

  2. Cosmic rays and neutrinos • What produces this spectrum? • Standard model: acceleration at relativistic astrophysical shocks R. Shellard, Braz. J. Phys 31 (2001)

  3. Why look for neutrinos? • Flux unattenuated over cosmological distances • Travel in straight lines (unlike cosmic rays) • Signatures of hadronic processes in the high-energy universe SNR GRB AGN jets and lobes Image courtesy of NRAO/AUI Image courtesy of NRAO/AUI NASA/Swift/Stefan Immler Nature 432 (2004) 75

  4. Quick note: these are not Solar neutrinos! • Production via cosmic-ray (~proton) interactions with: • Much rarer than solar neutrinos – but more energetic (GeV-PeV: not MeV) • νμ and ντ CC interactions possible low E proton Hadronic matter (interstellar gas) Photon fields (CMB)

  5. 3D PMTarray Cherenkov light from m 42° Earth’s crust (sea floor; Antarctic continent) m nm interaction Detection Principle p, a nm Optically transparent material (water; deep ice) p m nm nm Main detection channel: CC interactions ( NC, ande and  also). 5

  6. Let’s build it!

  7. The ANTARES Collaboration • University of Erlangen • Bamberg Observatory • Univ. of Wurzeburg • NIKHEF, • Amsterdam • Utrecht • KVI Groningen • NIOZ Texel • ITEP,Moscow • MoscowStateUniv • IFIC, Valencia • UPV, Valencia • UPC, Barcelona • ISS, Bucarest 8 countries 31 institutes ~150 scientists+engineers • CPPM, Marseille • DSM/IRFU/CEA, Saclay • APC, Paris • LPC, Clermont-Ferrand • IPHC, Strasbourg • Univ. de H.-A., Mulhouse • LAM, Marseille • COM, Marseille • GeoAzurVillefranche • INSU-DivisionTechnique • LPRM, Oujda • Univ./INFN of Bari • Univ./INFN of Bologna • Univ./INFN of Catania • LNS–Catania • Univ./INFN of Pisa • Univ./INFN of Rome • Univ./INFN of Genova 7

  8. ANTARES: Location • 40km off the coast of Toulon

  9. V. Bertin - CPPM - ARENA'08 @ Roma 2500m 450 m 70 m The ANTARES detector • 12lines • 25 storeys/line • 3 PMTs / storey • 885 10-inch PMTs • 10-20 Mton volume 40 km to shore Junction Box Interlink cables

  10. Sample events • Maximum-likelihood fit to recorded photon hit times http://www.pi1.physik.uni-erlangen.de/antares/online-display/online-display.php

  11. CRAB VELA SS433 ANTARES ‘visibility’ • ANTARES at 43o N • Sensitive to the Southern sky • Includes the Galactic Centre Never visible Invisible Increasing sensitivity ANTARES: 43o N Mkn 501 RX J1713.7-39 GX339-4 Galactic Centre Visible Always visible

  12. ANTARES performance: angular resolution • ~50% events reconstruct to better than 0.5o • ~99% reconstruct to better than 10o • Energy reconstruction is much harder (most is not ‘seen’) m n

  13. Muon and neutrino backgrounds • Remove atmospheric muon background with quality cuts • CR neutrino background irreducible p, a nm m p 1% misreconstruction Look for an excess here! Muon flux at 2500m depth from below from above

  14. Science with ANTARES • High-energy Neutrino Astrophysics • Galactic sources: SN & SNR, micro-quasars, CR in molecular clouds • Extra-galactic sources: AGN, GRB, GZK processes • Search for new physics: • Dark matter annihilation, nuclearites, monopoles • Earth sciences: • Oceanography, marine biology, seismology, environment monitoring… Oscillations DM SNR, μQSO AGN Exotics, GZK Marine biology GUT???

  15. Results!

  16. All-sky point-source search • Sky map in equatorial coordinates: • 2007-2010 data (813 days livetime) • 3058 candidates after cuts: expect 14% down-going muon contamination Most significant cluster: 2.2σ No strong evidence for a point-source excess

  17. Search from suspected sources • 51 pre-defined ‘suspect’ sources (mostly based on gamma-ray flux and visibility) • Top 11 sources: most significant first WR20a & b: hot, massive stars HESS, Astronomy & Astrophysics 467 (2007) 1075

  18. Neutrinos from gamma-ray bursts • ‘Fireball’ model for GRBs: • Explains long-duration bursts • Predicts neutrinos! • Search criteria: • Direction (2o from source) • Time (~1 minute) • Upcoming events only • Results from 2007 data (40 GRBs): no detection

  19. Neutrino Oscillations • Two-flavour mixing approximation: • Measureable: ‘Unknown’: • World data: 1st minimum at , (120 m max muon range) • Expectations for 863 days’ data: Events seen with two lines Events seen with one line No oscillations Best world data

  20. Oscillation analysis: results • After a Chi2minimisation to and two systematic variables: • 1st measurement of its type • Accepted July 2nd by Physics Letters B • Promising for next-generation larger detectors Combined single and multi-line data ANTARES K2K MINOS Super-K Data No oscillations Best fit 90% C.L. 68% C.L.

  21. Muon Flux Limits 90%CL (2007-2008) Search for Dark Matter Annihilation in the Sun • Lack of excess: => model limits (apologies: I do not have these plots here!) • A search for an excess from the galactic centre is ongoing  PRELIMINARY Angular distance from sun 21

  22. Search for magnetic monopoles • Relativistic monopoles emit VC radiation • 8550 times brighter than a muon • Look for extremely bright events! • ANTARES search space • Relativistic • ‘intermediate mass’ (< 1014GeV) • Search performed on data from 2008: • 1 event • 0.13 bkgd • 1.5 σ significance

  23. Multi-Messenger astronomy • Strategy: • Increase discovery potential (different probes) • Increase significance via coincidence Alerts • Ligo/Virgo (grav. waves) • Dedicated analysis chain • GW trigger • GCN (GRB) • Global burst network • GRB burst alert • ANTARES trigger and coincident analysis • TAROT (optical) • Follow-up search for SN • 10s repositioning

  24. Summary • ANTARES underwater neutrino telescope: • Largest neutrino telescope in the Northern Hemisphere • Proven ability to detect neutrino-induced muons • Good performance in bread & butter science: neutrino astrophysics • Sensitivity optimised for the galactic centre region • Diverse physics program: • Dark matter • Neutrino oscillations • Exotics (magnetic monopoles, nuclearites) • Entering ‘mature’ phase: • First round of results published (~1 year’s data) • Analyses on 3+ years of 12-line data in progress • More results on their way!

  25. (in case of tricky questions) Extra Slides

  26. Background and diffuse flux sensitivity • High energies favour source spectra • Background from atmospheric neutrinos: Enu-3.7 • Sources: order Enu-2 • Look for a high-energy excess! Limits on an E-2 flux E2F(E)90%= 5.3×10-8 GeV cm-2 s-1 sr-1 20 TeV<E<2.5 PeV Energy estimation: the ‘R’ parameter

  27. Standard data pipeline • ‘hit’: send PMT data to shore when one or more photons are observed • Raw data rate: too high to record • Trigger: Record data to disk if it looks `interesting’. • Standard trigger requirements: • Large ( ) hits OR hits on neighbouring PMTs (600 Hz) • Clusters of >=5 hits • Trigger hits must be causally connected • Many other triggers (GRB alert, monitoring info, GC etc) Threshold: 0.3 Vphoton PMT voltage Shore triggering and data acquisition 25 ns integration

  28. Candidate List Search – 90%CL Flux Limits Assumes E-2 flux for a possible signal ANTARES 2007-2010 813 days ANTARES has the most stringent limits for the Southern Sky

  29. Optical Background • Potassium 40 decay: constant background • Bioluminescence: large seasonal fluctuations • Bacteria • Vertebrates Image courtesy Wolfram Alpha Spring 2006 Spring 2007

  30. Trigger effective area • (preliminary plot: officially updated version will be out shortly)

  31. Data reduction for point-source search • Cut on angular-error estimate, and on fit quality

  32. Resolution: use the Moon’s shadow • The Moon blocks CR: expect reduction in the upcoming-event rate • 884 days’ livetime • 2.7 sigma defecit • Agrees with Monte Carlo expectations

  33. Storey 1 Storey 8 Storey 14 Storey 20 Storey 25 Sea currents and acousticpositioning Measure every 2 min: Distance line bases to 5 storeys/line and also storey headings and tilts Radial displacement Precision~ few cms

  34. 2006 – 2008: Building phase of the Detector ~70 m Junction box 2001 Main cable 2002 Line 1, 22006 Line 3, 4, 501 / 2007 Line 6, 7, 8, 9, 1012 / 2007 Line 11, 1205 / 2008

  35. Search for Neutrinos from Fermi Bubbles For 100% hadronicmodels: F ~1/2.5 F (Vissani) E2dF/dE=1.2*10-7 GeV cm-2s-1sr -1 E cutoff protons: 1PeV-10 PeV (Croker&Aharonian) E cutoff neutrinos = 1/20 cutoff protons Good visibility for ANTARES detector coords galacticcoords Background estimatedfrom average of three ‘OFF’ regions (time shifted in local coordinates)

  36. DarkMatterSimulation MWIMP = 350 GeV M A I N A N N I H I L A T I O N C H A N N E L S mUEDparticular case… τ leptons regeneration in the Sun

  37. Dark matter – detector performance • ANTARES effective area to muon neutrinos incident on Earth • Most neutrinos do not produce detectable muons • Most muons are very low in energy

  38. Magnetic Monopoles: data reduction • Magnetic monopoles… • Theoretical prediction (quantisation of charge, guage theories…) • Have not been observed (various limits exist) • Have a magnetic charge g: will emit Vavilov-Cherenkov radiation • VC radiation: 8550 times brighter than that of a muon with similar velocity • Acceleration in cosmic magnetic fields

  39. Muon Flux Limits 90%CL (2007-2008) Search for Dark Matter Annihilation in the Sun  PRELIMINARY Angular distance from sun PRELIMINARY 39