A Sterile Neutrino Origin for the Upward Directed Cosmic Ray Shower Detected by ANITA

Dr. JJ Cherry (host Dev), University of South Dakota
February 8, 2018 at 3:00 pm
241 Compton
Event Description 

The ANITA balloon experiment has recently observed an ~EeV cascade event at an angle below the horizon that renders any Standard Model (SM) interpretation unlikely as the Earth is significantly opaque to all SM particles at such energies. In this paper, we study a sterile neutrino interpretation of this event, calculating the angular event distribution of cascades and the relative sensitivities of several experiments to a cascade initiated by an EeV sterile neutrino. A natural flux of sterile neutrinos at EeV energies can arise from either a dark matter decay process or the reprocessing of Ultra High Energy Cosmic Ray (UHECR) neutrinos into the sterile state through a hidden gauge interaction. We find that ANITA is uniquely sensitive to this type of upward directed cascade signal and that canonical UHECR models can produce a reprocessed EeV sterile neutrino flux at sufficient levels to accommodate the ANITA event.

Coffee: 2:45 pm, 241 Compton