Atmospheric neutrino flux supported by recent muon experiments

We present a new one-dimensional calculation of low and intermediate energy atmospheric muon and neutrino fluxes, using up-to-date data on primary cos mic rays and hadronic interactions. We study several sources of uncertainti es relevant to our calculations. A comparison with the muon fluxes and char ge ratios measured in several modern balloon-borne experiments suggests tha t the atmospheric neutrino flux is essentially lower than one used for the standard analyses of the sub-GeV and multi-GeV neutrino induced events in u nderground detectors. (C) 2001 Elsevier Science B,V, All rights reserved.