Quantum mechanics

Neutrino oscillation

COSMIC cancer database

Cosmic ray spallation

Metallurgy

Materials science

Cosmic ray

Nuclear physics

Particle physics

Astrophysics

Hadron

Neutrino

Photon

Physics

Neutrino detector

Flux (metallurgy)

Ultra-high-energy cosmic ray

Physical review. D/Physical review. D.

Cosmogenic neutrinos are produced when ultra-high-energy cosmic rays (UHECRs) interact with cosmological photon fields. Limits on the diffuse flux of these neutrinos can be used to constrain the fraction of protons arriving at Earth with energies $E_{p} \gtrsim 30$ EeV, thereby providing constraints on the composition of UHECRs without fully relying on hadronic interaction models. We show to which extent current neutrino telescopes already constrain this fraction of protons and discuss the prospects for next-generation detectors to further constrain it. Additionally, we discuss the implications of these limits for several popular candidates for UHECR source classes.

Determining the fraction of cosmic-ray protons at ultrahigh energies with cosmogenic neutrinos