Status of solar neutrino observation at Super-Kamiokande

Super-Kamiokande has observed solar neutrinos from the Sun since 1996. From recent result from 1258 days measurement, the obtained 8B solar neutrino flux is 2.32±0.03(stat.)+0.08−0.07×106 cm−2 s−1. According to the zenith spectrum analysis, Super-Kamiokande disfavors not only the small mixing angle solution and Just So solution for 2 flavor active neutrino oscillation, but also the fully 2 flavor sterile neutrino oscillation at 95% C.L. even without any flux constraint. Concerning both results from Super-Kamiokande and SNO, a neutrino oscillation is naturally established in the 8B solar neutrinos measurement, and also the small mixing angle solution is disfavored by 3 sigma.