Random magnetic fields inducing solar neutrino spin-flavor precession in a three generation context

We study the effect of random magnetic fields in the spin-flavor precession of solar neutrinos in a three generation context, when a nonvanishing transition magnetic moment is assumed. While this kind of precession is strongly constrained when the magnetic moment involves the first family, such constraints do not apply if we suppose a transition magnetic moment between the second and third families. In this scenario we can have a large nonelectron antineutrino flux arriving on Earth, which can lead to some interesting phenomenological consequences, as, for instance, the suppression of day-night asymmetry. We have analyzed the high-energy solar neutrino data and the KamLAND experiment to constrain the solar mixing angle, theta, and solar mass difference, Delta m(2), and we have found a large shift of allowed values. Also, sizable effects in the Borexino experiment are expected which can discriminate this scenario and standard large mixing angle solution to the solar neutrino problem.