First results of the ANTARES neutrino telescope

Abstract

The ANTARES Collaboration successfully completed in May 2008 the deployment of an underwater neutrino detector in the Mediterranean Sea, offshore the France coast, at 2475 m b.s.l. The main purpose of this experiment is the detection of high energy neutrinos produced in astrophysical sources. Neutrinos being neutral, stable and weakly interacting particles can travel undeflected trough the Universe reaching the Earth even from the inner core of very distant objects. They are therefore very powerful messengers which can provide us invaluable information about processes which are hardly accessible with other messengers like photons. The detection of astrophysical neutrinos is very challenging due to the very small neutrino interaction cross-section and the huge background produced by other cosmic rays. Very large instrumented volumes and a very efficient shielding are therefore needed to detect astrophysical neutrinos. Moreover a very good angular resolution is mandatory to trace detected neutrinos back to their origin. ANTARES with 0.04 km2 muon effective area at Ev > 10 TeV shielded by more than 2000 m of water and an angular resolution of 0.3° at Ev > 10 TeV, perfectly fits these requirements. The ANTARES deployment started in 2006 and many data have been already collected with a partial detector. The detector in its final configuration is described and preliminary results of data analysis, especially about calibration issues, are shown. The completion of the ANTARES detector paved the way towards an even larger submarine neutrino telescope in the Mediterranean Sea like the one planned by the KM3NeT project.