Muon Fluxes Derived From the Directly Measured Primary Cosmic Ray Elemental Spectra

Abstract

The muon energy spectra at 0° and 89° have been estimated from the decay of nonprompt and prompt mesons created by the individual elemental primary cosmic ray groups during nucleus-air collisions in the upper atmosphere and the results are found to be fairly comparable with the measured muon fluxes obtained from the direct magnetic spectrograph results in Refs. 2–4, and also from the underground indirect measurements in Refs. 5–10. The muon spectrum derived from the single slope primary nucleon spectrum with a constant spectral index of value −2.73 is only slightly different from the present result for energies below 20 TeV. The present muon spectra at large zenith angle exhibit steeper spectral indices when compared to the expected results obtained from primary elemental groups by Parente et al.