Solar Model Uncertainties, MSW Analysis, and Future Solar Neutrino Experiments

Various theoretical uncertainties in the standard solar model and in the Mikheyev-Smirnov-Wolfenstein (MSW) analysis are discussed. It is shown that two methods of estimating the solar neutrino flux uncertainties are equivalent: (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 correlation of theoretical uncertainties between flux components and between different detectors, the Earth effect, and multiple solutions in a combined ${\chi }^2$ procedure. The MSW solutions for various standard and nonstandard solar models are also shown. The MSW predictions of the global solutions for the future solar neutrino experiments are given, emphasizing the measurement of the energy spectrum and the day-night effect in Sudbury Neutrino Observatory and Super-Kamiokande to distinguish the two solutions.