Search for a diffuse flux of cosmic neutrinos with the ANTARES telescope

Abstract

The ANTARES detector is the largest neutrino telescope in the Northern Hemisphere. Interactions of all neutrino flavours can be observed and reconstructed by the experiment. Events induced by muon neutrino charged-current interactions represent the track channel: the long path travelled by muons before being detected allows to increase the effective detector volume, with excellent angular resolution but limited precision in the event energy reconstruction. The shower channel, i.e. all neutral-current and charged-current interactions of electron neutrinos (and possibly tau neutrinos ) allows for a better energy resolution than the track channel, though only events within a limited fiducial volume can be considered. Exploiting its multi-year dataset, the complementarity of its field of view and its excellent reconstruction performance, ANTARES can independently investigate the cosmic neutrino flux reported by the Antarctic IceCube detector. The latest results of these all-flavour searches for a diffuse astrophysical neutrino flux are presented in this contribution. Using events observed in both channels, an excess of events with respect to the expected atmospheric background is observed with a significance below 2σ. Once systematics are included, the corresponding 68% confidence interval encloses the observed IceCube signal.