Current Status of the Solar Neutrino Problem with Super-Kamiokande

Abstract

We perform an updated model-independent analysis using the latest solar neutrino data obtained by $^{37}$Cl and $^{71}$Ga radiochemical experiments, and most notably by a large water-Cherenkov detector SuperKamiokande with their 504 days of data taking. We confirm that the astrophysical solutions to the solar neutrino problem are extremely disfavored by the data and a low-temperature modification of the standard solar model is excluded by more than 5 $\sigma$. We also propose a new way of illuminating the suppression pattern of various solar neutrino flux without invoking detailed flavor conversion mechanisms. It indicates that the strong suppression of $^7$Be neutrinos is no more true when the neutrino flavor conversion is taken into account.