Solar Neutrino Data, Neutrino Magnetic Moments and Flavor Mixing

Abstract

The results of all currently operating solar neutrino experiments are analyzed in the framework of the resonant neutrino spin--flavor precession scenario including the effects of neutrino mixing. Nine different profiles of the solar magnetic field are used in the calculations. It is shown that the available experimental data can be accounted for within the considered scenario. The Ga--Ge data lead to an upper limit on the neutrino mixing angle: $\sin 2θ_0 \aprle 0.25$. One can discriminate between small mixing angle ($\sin 2θ_0 \aprle 0.1$) and moderate mixing angle solutions by studying the solar $\barν_{e}$ flux which is predicted to be sizeable for moderate mixing angles. The expected signals due to $\barν_{e}$ in the SNO, Super--Kamiokande and Borexino experiments are calculated and found to be detectable for $\sin 2θ_0 \aprge 0.1$.