Cosmic-ray muons at ultrahigh energies

Abstract

Fluxes of cosmic-ray muons were estimated over the energy range extending up to 10¹⁰ GeV. Data on the production of pions; kaons; η, η′, ρ, ω, and ϕ mesons; charmed particles; and J/ψ mesons from accelerator experiments devoted to studying interactions between nucleons and nuclei of air atoms up to nucleon energies of about 2 × 10⁴ GeV were used in respective calculations. At higher energies, use was made of the results obtained by calculating cross sections for the production of charmed particles and J/ψ mesons on the basis of QCD models. It is shown that, in interpreting experimental data on extensive air showers, the production of both charmed particles and J/ψ mesons in the Earth’s atmosphere must be taken into account.