Study of the Solar Neutrino Survival Probability

We present a study of recent solar neutrino data using a Bayesian method. Assuming that only ${\nu }_e$ are observed in the Super-Kamiokande experiment our results show a marked suppression of the survival probability at about 1 MeV, in good agreement with ${\chi }^2$-based analyses. When the detection of ${\nu }_{\mu }$ by Super-Kamiokande is taken into account, assuming ${\nu }_e$ to ${\nu }_{\mu }$ oscillations, we find the largest suppression in survival probability at about 8.5 MeV.