Indirect Dark Matter search with the ANTARES Deep-Sea Cherenkov detector

摘要

In 2008 the ANTARES collaboration completed the construction of an underwater neutrino telescope in the Mediterranean Sea, located 40 km off the French coast at a depth of 2475 m. With an effective area for upward muon detection of about 0.05 km2, depending on neutrino energy, ANTARES is the largest neutrino detector currently operating in the Northern hemisphere. The experiment aims to detect high-energy neutrinos up to 104 TeV using a 3-dimensional array of 885 photomultipliers distributed in 25 storeys along 12 vertical lines. The detection is based on the measurement of Cherenkov light emitted by charged leptons resulting from charged-current neutrino interactions in the matter surrounding the telescope. The accurate measurements of the photon arrival times and of the deposited charge together with a precise knowledge of the actual positions and orientations of the photo sensors allow the reconstruction of the direction of neutrinos with good angular resolution (about 0.3° for muon neutrinos above a few TeV) and of their energy. ANTARES is performing an indirect search for dark matter by looking for a statistical excess of neutrinos coming from astrophysical massive objects, such as the Sun, the Earth and the Galactic Centre. This excess could be an evidence of the possible annihilation of dark matter particles in the centre of these objects. In the most accepted scenario, the dark matter is composed by WIMP particles. These particles can be scattered by the nuclei of these astrophysical bodies and get gravitationally trapped, accumulating in their inner core. Here they can interact with other WIMPs, in self-annihilation reactions, producing some standard model particles that, in subsequent steps, originate neutrinos that can be detected at Earth. The preliminary results of the sensitivity of the ANTARES neutrino telescope to the indirect detection of dark matter fluxes will be presented for different dark matter models.