High Energy Neutrinos and Cosmic Rays

TL;DR

This paper reviews the current experimental and theoretical understanding of ultra-high energy cosmic rays and neutrinos, highlighting open questions about their origins, compositions, and the constraints from recent experimental limits.

Contribution

It provides a comprehensive overview of the status of high energy cosmic radiation research, emphasizing the challenges and recent constraints on source models and acceleration mechanisms.

Findings

Neutrinos at GeV energies from extraterrestrial sources have not yet been detected.

Experimental upper limits are constraining models of cosmic ray sources.

Key open questions involve the composition and sky distribution of ultra-high energy particles.

Abstract

This is a summary of a series of lectures on the current experimental and theoretical status of our understanding of origin and nature of cosmic radiation. Specific focus is put on ultra-high energy cosmic radiation above ~10^17 eV, including secondary neutral particles and in particular neutrinos. The most important open questions are related to the mass composition and sky distributions of these particles as well as on the location and nature of their sources. High energy neutrinos at GeV energies and above from extra-terrestrial sources have not yet been detected and experimental upper limits start to put strong contraints on the sources and the acceleration mechanism of very high energy cosmic rays.