Neutrino Magnetic Moments and the Solar Neutrino Problem

Abstract

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin--flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles ($\sin 2\theta_0 \aprge 0.2$) the combined effect of the resonant spin--flavor precession and neutrino oscillations can result in an observable flux of solar $\bar{\nu}_{e}$'s.