Sea level muon spectra at large zenith angles derived from the latest JACEE primary nucleon spectrum

Summary Sea level muon energy spectra at large zenith angles have been derived from the latest JACEE primary spectrum using the Fermilab Single-Arm Spectrometer data on charged-meson production. The role of increasing total cross-section on the final result for the energy spectra has been investigated here with special emphasis. The inclusion of the rising total cross-section at cosmic range of energies, it is seen, has come into much use in explaining the observed data at very high energies. The autors of this paper have agreed not to receive the proofs for correction.