Matter Effects in Solar Neutrino Active-Sterile Oscillations

Abstract

We study the matter effects for solar neutrino oscillations in a general scheme, without any constraint on the number of sterile neutrinos and the mixing matrix elements, only assuming a realistic hierarchy of neutrino squared-mass differences in which the smallest squared-mass difference is effective in solar neutrino oscillations. The validity of the analytic results are illustrated with a numerical solution of the evolution equation in the simplest case of four-neutrino mixing with the realistic matter density profile inside the Sun.

Comments: 3 pages 1 figure, based on talk YFL gave at Erice 2009 Neutrinos in Cosmology, in Astro-, Particle- and Nuclear Physics