Effects of $e^- e^+ ν_e$ Decays of Tau Neutrinos Near A Supernova

Abstract

We revisit the constraints implied by SN 1987 A observations on the decay rate of a multi-MeV $ν_τ$ decaying into the visible channel $ν_τ\rightarrow e^+ e^- ν_e$, if its lifetime is more than 10 {\it sec.}. We discuss its implication for the minimal left-right symmetric model with see-saw mechanism for neutrino masses. We also speculate on the possible formation of a ``giant Capacitor" in intergalactic space due to the decay of "neutronization" $ν_τ$'s and spin allignment possibility in the supernova.