Neutrino probe of cosmic ray astrophysics and new physics at sub-fermi distances

TL;DR

This paper explores how cosmic ray source evolution impacts tau neutrino flux limits and discusses potential to detect new leptophobic interactions with future observatory data.

Contribution

It links cosmic ray source evolution to neutrino flux constraints and proposes methods to identify new physics interactions.

Findings

Tau neutrino flux limits constrain proton fractions in cosmic rays.

Future data could reveal leptophobic new physics interactions.

Cosmic ray source evolution influences neutrino detection prospects.

Abstract

We show that if the evolution of cosmic ray sources follows that of active galactic nuclei, the upper limit on the diffuse flux of tau neutrinos from the Pierre Auger Observatory marginally constrains the proton fraction at the end of the energy spectrum. We also discuss prospects to uncover new physics leptophobic interactions using future Auger data.