Does the neutrino magnetic moment have an impact on solar neutrino physics?

Solar neutrino observations coupled with the recent KamLAND data suggest that spin-flavor precession scenario does not play a major role in neutrino propagation in the solar matter. We provide approximate analytical formulas and numerical results to estimate the contribution of the spin-flavor precession, if any, to the electron neutrino survival probability when the magnetic moment and magnetic field combination is small.

Figure 1

Electron neutrino survival probability as a function of neutrino energy in presence of both the MSW and the SFP resonances. In particular, a Gaussian magnetic field profile is taken, with a magnetic field of ${10}^5\mathrm{G}$ and a magnetic moment of ${10}^{-11}{\mu }_B$. The location of the resonances are given in Table . The results shown are indistinguishable from those due to the MSW resonance only, at least at the level of ${10}^5$.