Updated global analysis of the atmospheric neutrino data in terms of neutrino oscillations

A global analysis of all the available atmospheric neutrino data is presented in terms of neutrino oscillations in the nu(mu) --> nu(tau) and nu(mu) --> nu(s) channels, where vs denotes a sterile neutrino. We perform our analysis of the contained events data as well as the upward-going neutrino-induced muon fluxes. in addition to the previous data samples of Frejus, Nusex, IMB and Kamioka experiments, we include the full data set of the 52 kton-yr of Super-Kamiokande, the recent 4.6 kton-yr contained events of Soudan2 and the results on upgoing muons from the MACRO and Baksan detectors. From the statistical analysis it emerges that the nu(mu) --> nu(tau) channel provides the best agreement with the combined data, with a best fit point of sin(2)(2 theta) = 0.99 and Delta m(2) = 3.0 x 10(-3) eV(2). Although somehow disfavoured, the nu(mu) --> nu(s) channels cannot be ruled out on the basis of the: global fit to the full set of observables. (C) 2000 Elsevier Science B.V. All rights reserved.