Neutrinos from stellar collapse: Effects of flavor mixing

Abstract

We study the effect of nonvanishing masses and mixings among neutrino flavors on the detection of neutrinos from stellar collapse by a water Cherenkov detector. We consider a realistic framework in which there are three neutrino flavors whose mass squared differences and mixings are constrained by the present understanding of solar and atmospheric neutrinos. We also include the effects of high dense matter within the supernova core. We find that the number of events due to the dominant process involving electron antineutrinos may change dramatically for some allowed mixing parameters. Furthermore, contributions from charged-current scattering off oxygen atoms in the detector can be considerably enhanced due to flavor mixing; such events have a distinct experimental signature since they are backward peaked. ©1999 The American Physical Society.