SOLAR MODEL UNCERTAINTIES, MSW ANALYSIS, AND FUTURE SOLAR-NEUTRINO EXPERIMENTS

Various theoretical uncertainties in the standard solar model and in t he Mikheyev-Smirnov-Wolfenstein (MSW) analysis are discussed. It is sh own that two methods give consistent estimations of the solar neutrino flux uncertainties: (a) a simple parametrization of the uncertainties using the core temperature and the nuclear production cross sections; (b) the Monte Carlo method of Bahcall and Ulrich. In the MSW analysis , we emphasize proper treatments of correlations of theoretical uncert ainties between flux components and between different detectors, the E arth effect, and multiple solutions in a combined chi2 procedure. In p articular the large-angle solution of the combined observation is allo wed at 95% C.L. only when the theoretical uncertainties are included. If their correlations were ignored, the region would be overestimated. The MSW solutions for various standard and nonstandard solar models a re also shown. The MSW predictions of the global solutions for the fut ure solar neutrino experiments are given, emphasizing the measurement of the energy spectrum and the day-night effect in Sudbury Neutrino Ob servatory and Super-Kamiokande to distinguish the two solutions.