Recent results of super-kamiokande

The recent results of atmospheric and solar neutrino measurements in the first (SK-I) and second (SK-II) phase of Super-Kamiokande were presented. The neutrino oscillation analysis in atmospheric neutrino was discussed. The best-fit parameters of (Δm², sin² 2θ) = (2.5×10^-3 eV², 1.0) which was combined in SK-I and SK-II were obtained with v_μ ↔ v_τ two-flavor oscillation model using zenith angle analysis. Other hypotheses to explain the atmospheric neutrino data were not well supported using L/E analysis method. The three-flavor oscillation analysis was also applied. No significant enhancement due to matter effect, which occurs when neutrinos propagate inside the Earth on the condition of θ₁₃ ≠0, cannot be seen. The results of solar neutrino data from SK-I and SK-II were presented. Super-Kamiokande can measure not only the solar neutrino flux but also its energy spectrum and time variations such as day-night and seasonal differences. The detail oscillation analysis using those information are applied to SK-I data. Combining SK and SNO data, the obtained oscillation parameters becomes so-called 'LMA' solution. And also three-flavor oscillation analysis was applied to solar neutrino data, the upper limit for sin² θ₁₃ is 0.067 at 90%C.L.