CRA Seminar: Ibrahim Safa (Columbia)

Title: Hunting extragalactic tau neutrinos in mountains, canyons, and volcanoes

Abstract: The IceCube neutrino observatory discovered a high energy astrophysical neutrino flux extending to ~10PeV in energy. A first generation extragalactic neutrino telescope, IceCube gave us a taste of mulitmessenger astronomy with several reported hints thus far. An upcoming generation of telescopes is in the works, promising a further reach into EeV energies. Many of these proposed experiments rely on natural dense media like mountains, volcanoes, and canyons to capture neutrinos. In particular, the tau neutrino has unique propagation properties that boost the prospects of such detections. I will first discuss how a better understanding of astrophysical neutrino flavors provides a smoking gun signature to new physics at yet unexplored energy scales. Then I will present the challenges that lie ahead before such signatures can be detected. I will also briefly describe the proposed experiments and their expected sensitivities.