Supernova Bounds on Resonant Active-Sterile Neutrino Conversions

Abstract

We discuss the effects of resonant $ν_e \to ν_s$ and $\barν_e \to \barν_s$ ($ν_s$ is a sterile neutrino) conversions in the dense medium of a supernova. In particular, we assume the sterile neutrino $ν_s$ to be in the hot dark matter few eV mass range. The implications of such a scenario for the supernova shock re-heating, the detected $\barν_e$ signal from SN1987A and for the r-process nucleosynthesis hypothesis are analysed in some detail. The resulting constraints on mixing and mass difference for the $ν_e-ν_s$ system are derived. There is also an allowed region in the neutrino parameter space for which the r-process nucleosynthesis can be enhanced.

Latex file, 27 pages including 10 ps figures, uses psfig.sty. Few references added, some change in the Acknowledgements and some minor corrections in the text