A MONTE-CARLO CALCULATION OF ATMOSPHERIC MUON AND NEUTRINO FLUXES

Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with a cascade simulation program bas ed on Lund Monte Carlo programs. The resulting 'conventional' muon and neutrino fluxes (from pi, K decays) agree well with earlier calculati ons, whereas the improved charm particle treatment used in this study gives significantly lower 'prompt' fluxes compared to earlier estimate s. This implies better prospects for detecting very high energy neutri nos from cosmic sources.