Comparison of high-energy galactic and atmospheric tau neutrino flux

Abstract

We compare the tau neutrino flux arising from the galaxy and the earth atmosphere for 10(3) less than or equal to E/GeV less than or equal to 10(11). The intrinsic and oscillated tau neutrino fluxes from both sources are calculated. The intrinsic galactic nu(tau) flux (E greater than or equal to 10(3) GeV) is calculated by considering the interactions of high-energy cosmic-rays with the matter present in our galaxy, whereas the oscillated galactic nu(tau) flux is coming from the oscillation of the galactic nu(mu) flux. For the intrinsic atmospheric nu(tau) flux, we extend the validity of a previous calculation from E less than or equal to 10(6) GeV up to E less than or equal to 10(11) GeV. The oscillated atmospheric nu(tau) flux is, on the other hand, rather suppressed. We find that, for 10(3) less than or equal to E/GeV less than or equal to 5 x 10(7), the oscillated nu(tau) flux along the galactic plane dominates over the maximal intrinsic atmospheric nu(tau) flux, i.e., the flux along the horizontal direction. We also briefly mention the presently envisaged prospects for observing these high-energy tau neutrinos. (C) 2002 Elsevier Science B.V. All rights reserved.