Implications of new GALLEX results for the Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem

Abstract

We compare the implications for ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ and pp neutrinos of the two Mikheyev-Smirnov-Wolfenstein fits to the new GALLEX solar neutrino measurements. Small-mixing-angle solutions tend to suppress the former as electron neutrinos, but not the latter, and large-angle solutions tend to reduce both by about a factor of 2. The consequences for BOREXINO and similar solar neutrino-electron scattering experiments are discussed.