New Solar-Neutrino Flux Calculations and Implications Regarding Neutrino Oscillations

The results of new calculations of solar-neutrino fluxes are presented; the fluxes are obtained from detailed solar models that make use of improved opacities and nuclear-physics cross sections. By evaluating known uncertainties in the predicted capture rate for the $^{37}\mathrm{Cl}$ solar-neutrino experiment, we find that the ratio of theoretical to (best-estimate) observed capture rate lies in the range 4.0 to 2.6. These results constitute a strong constraint on models of neutrino oscillations if the entire discrepancy is ascribed to neutrino oscillations.