Ultra High Energy Cosmic Ray, Neutrino, and Photon Propagation and the Multi-Messenger Approach

TL;DR

This paper reviews the propagation of ultra-high-energy cosmic rays, neutrinos, and photons, discussing secondary particle production and how multi-messenger observations can reveal properties of UHECR sources and their local environment.

Contribution

It provides a comprehensive multi-messenger framework combining cosmic ray, neutrino, and photon data to better understand UHECR origins and source characteristics.

Findings

Diffuse cosmogenic UHE-neutrino flux predictions

Constraints on UHECR source radiation fields

Insights into local UHECR source populations

Abstract

The propagation of UHECR nuclei for A=1 (protons) to A=56 (iron) from cosmological sources through extragalactic space is discussed in the first lecture. This is followed in the second and third lectures by a consideration of the generation and propagation of secondary particles produced via the UHECR loss interactions. In the second lecture we focus on the generation of the diffuse cosmogenic UHE-neutrino flux. In the third lecture we investigate the arriving flux of UHE-photon flux at Earth. In the final lecture the results of the previous lectures are put together in order to provide new insights into UHECR sources. The first of these providing a means with which to investigate the local population of UHECR sources through the measurement of the UHECR spectrum and their photon fraction at Earth. The second of these providing contraints on the UHECR source radiation fields through the possible observation at Earth of UHECR nuclei.