Super-Kamiokande atmospheric neutrino results

Abstract

We present atmospheric neutrino results from a 79 kiloton year (1289 days) exposure of the Super-Kamiokande detector. Our data are well explained by $\nu_{\mu} \to \nu_{\tau}$ 2-flavor oscillations. We have been attempting to discriminate between the possible oscillating partners of the muon neutrino as being either the tau neutrino or the sterile neutrino. Pure $\nu_\mu\to\nu_s$ oscillation is disfavored at 99% C.L.. Moreover, we performed the appearance search for charged current tau neutrino interactions in the upward-going samples. Our data is consistent with $\nu_{\tau}$ appearance at roughly the two-sigma level.