Matter Effects in Active-Sterile Solar Neutrino Oscillations

TL;DR

This paper investigates how matter effects influence solar neutrino oscillations in models with multiple sterile neutrinos, providing analytic results validated by numerical examples.

Contribution

It offers a general analytic framework for matter effects in active-sterile neutrino oscillations with arbitrary mixing, under realistic mass hierarchy assumptions.

Findings

Analytic expressions for matter effects in multi-sterile neutrino models.

Numerical validation of analytic results in four-neutrino mixing scenarios.

Insights into the role of sterile neutrinos in solar neutrino oscillations.

Abstract

The matter effects for solar neutrino oscillations are studied in a general scheme with an arbitrary number of sterile neutrinos, without any constraint on the mixing, assuming only 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 three examples of the possible mixing matrix in the simplest case of four-neutrino mixing.