AN UPDATE ON THE SOLAR NEUTRINO PROBLEM AND THE 3-FAMILY MSW EFFECT ALLOWING FOR ASTROPHYSICAL UNCERTAINTIES

Three-neutrino MSW mixing is considered, assuming m3(2) much greater than m2(2) much greater than m1(2) as expected from theoretical considerations, and the corresponding allowed mixing parameter space is calculated from the Cl-37 and Kamiokande II experiments. The expected depletion for the Ga-71 experiment is also calculated. The possible variations induced by a range of astrophysical uncertainty is explored by varying the B-8 neutrino flux and redoing the MSW mixing calculation with such variations, including the consistency with the possible atmospheric neutrino mixing observations.