Author/Authors :
N. Fornengo، نويسنده , , M.C. Gonzalez-Garcia، نويسنده , , J.W.F. Valle، نويسنده ,
Abstract :
A global analysis of all the available atmospheric neutrino data is presented in terms of neutrino oscillations in the νμ→ντ and νμ→νs channels, where νs 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 Fréjus, 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 νμ→ντ channel provides the best agreement with the combined data, with a best fit point of sin2(2θ)=0.99 and Δm2=3.0×10−3 eV2. Although somehow disfavoured, the νμ→νs channels cannot be ruled out on the basis of the global fit to the full set of observables.