MSW effects on high-energy solar neutrinos from relic annihilation

Abstract

We demonstrate that Mikheyev-Smirnov-Wolfenstein (MSW) matter oscillations can alter significantly the fluxes of high-energy (GeV) solar neutrinos, produced for example by the annihilation of cold dark matter particles in the solar core. We use as illustrations models of neutrino masses and mixings motivated by the low-energy solar neutrino data, and show that the flux of ν e may be dramatically enhanced and the flux of ν μ,τ correspondingly suppressed, or vice versa. This possible high-energy MSW effect is therefore a source of ambiguity in the interpretation of experimental searches for dark matter annihilations inside the Sun, as we discuss explicitly for sneutrinos, and could eventually be used to descriminate between different solutions to the low-energy solar neutrino problem.