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

X iv :h ep -p h/ 05 04 18 5 v1 20 A pr 2 00 5 Random magnetic fields inducing solar neutrino spin-flavor precession in a three generation context M. M. Guzzo, P. C. de Holanda, and O. L. G. Peres 1 Instituto de F́ısica Gleb Wataghin UNICAMP, 13083-970 Campinas SP, Brazil 2 Instituto de F́ısica, Universidade de São Paulo, 05315-970, São Paulo SP, Brazil We study the effect of random magnetic fields in the spin-flavor precession of solar neutrinos in a three generation context, when a non-vanishing 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 non-electron anti-neutrino 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, tan θ⊙, and solar mass difference, ∆m2⊙, and we have found a larger shift of allowed values.