Analysis of a tau neutrino origin for the near-horizon air shower events observed by the fourth flight of the Antarctic Impulsive Transient Antenna

We study in detail the sensitivity of Antarctic Impulsive Transient Antenna (ANITA) to possible ντ point source fluxes detected via τ-lepton-induced air showers. This investigation is framed around observation four upward-going extensive shower events very close horizon seen ANITA-IV. find that these upgoing are not observationally inconsistent with τ-induced EASs from Earth-skimming both their spectral properties as well observed locations on sky. These overall diffuse and exposure also compared against published ultrahigh-energy neutrino limits Pierre Auger Observatory. While none occurred at sky simultaneously visible by Auger, implied fluence necessary for ANITA observe strong tension set across a wide range energies additionally ANITA’s Askaryan in-ice channel above 1019 eV. conclude discussing some technical challenges simulating analyzing near potential future observatories similar events.14 MoreReceived 12 October 2021Accepted 29 November 2021DOI:https://doi.org/10.1103/PhysRevD.105.042001© 2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasParticle astrophysicsTechniquesCosmic ray & astroparticle detectorsNeutrino detectorsParticles Fields