Probing nonstandard neutrino interactions with supernova neutrinos

Abstract

We analyze the possibility of probing nonstandard neutrino interactions (NSI, for short) through the detection of neutrinos produced in a future galactic supernova (SN). We consider the effect of NSI on the neutrino propagation through the SN envelope within a three-neutrino framework, paying special attention to the inclusion of NSI-induced resonant conversions, which may take place in the most deleptonized inner layers. We study the possibility of detecting NSI effects in a Megaton water Cherenkov detector, either through modulation effects in the ν̄e spectrum due to (i) the passage of shock waves through the SN envelope, (ii) the time dependence of the electron fraction, and (iii) the Earth matter effects; or, finally, through the possible detectability of the neutronization νe burst. We find that the ν̄e spectrum can exhibit dramatic features due to the internal NSI-induced resonant conversion. This occurs for nonuniversal NSI strengths of a few %, and for very small flavor-changing NSI above a few×10-5. © 2007 The American Physical Society.