Reviving the energy independent suppression of the solar neutrino flux

Abstract

We explore the possibility of an energy independent suppression of the solar neutrino flux in the context of the recent SuperKamiokande data. From a global analysis of the rate and spectrum data, this scenario is allowed at only 14% probability with the observed Cl rate. If we allow for a 20% upward renormalisation of the Cl rate along with a downward renormalisation of the $B$ neutrino flux then the fit improves considerably to a probability of $\sim 50%$. We compare the quality of these fits with those of the MSW solutions. These renormalisations are also found to improve the quality of the fits with MSW solutions and enlarge the allowed region of their validity in the parameter space substantially. Over much of this enlarged region the matter effects on the suppression of the solar neutrino flux are found to be very weak, so that the solutions become practically energy independent.