Ultra High Energy Cosmic Rays and Neutrinos

TL;DR

This paper explores the origins and detection of ultra high energy neutrinos from cosmic rays, emphasizing their role in understanding cosmic ray composition and potential new physics linked to cosmological observations.

Contribution

It highlights the significance of ultra high energy neutrino detection in diagnosing cosmic ray composition and probing new physics at extreme energies.

Findings

Neutrino detection can clarify cosmic ray composition discrepancies.

Ultra high energy neutrinos may reveal new physics related to cosmological tensor modes.

Propagation models link cosmic rays to neutrino production.

Abstract

We discuss the production of ultra high energy neutrinos coming from the propagation of ultra high energy cosmic rays and in the framework of top-down models for the production of these extremely energetic particles. We show the importance of the detection of ultra high energy neutrinos that can be a fundamental diagnostic tool to solve the discrepancy in the observed chemical composition of ultra high energy cosmic rays and, at the extreme energies, can unveil new physics in connection with the recent cosmological observations of the possible presence of tensor modes in the fluctuation pattern of the cosmic microwave background.