Can transition radiation explain the ANITA event 3985267?

Understand

We investigate whether transition radiation from a particle shower crossing the interface between Earth and air and induced by an Earth-skimming neutrino can explain the upward event announced recently by the ANITA Collaboration.

• While the properties of the observed signal can in principle be explained with transition radiation, the flux necessary for a successful explanation is in tension with the current best limits from the Pierre Auger Observatory, the IceCube neutrino detector and the ANITA balloon.
• We also show that in this scenario, the direction of the incoming neutrino is determined precisely to within a few degrees, from the polarization properties of the observed events and thanks to the Earth opacity to ultra high energy neutrinos.