Atmospheric neutrinos: Latest results from Super-Kamiokande Original Research Article

Atmospheric neutrino data from Super-Kamiokande are presented. The Super-Kamiokande detector started observation on April 1996 and a 92 kiloton-yr(1489 live-day) exposure to atmospheric neutrino was achieved until July 2001 during the Super-Kamiokande first period(SK-I). We present the latest atmospheric neutrino data. The data are consistent with νμ ↔ ντ two flavor neutrino oscillations. The allowed oscillation parameters are 1.6 × 10−3 < Δm2 < 3.9 × 10−3eV2 and sin2 2θ > 0.92 at 90% confidence level.