Production of unstable heavy neutrinos in proto-neutron stars

Abstract

We discuss the production of a class of heavy sterile neutrinos nu(h) in proto-neutron stars. The neutrinos, of mass around 50 MeV, have a negligible mixing with the active species but relatively large dimension-5 electromagnetic couplings. In particular, a magnetic dipole moment mu approximate to 10(-6) GeV-1 implies that they are thermally produced through e(+)e(-) -> (nu) over bar (h)nu(h) in the early phase of the core collapse, whereas a heavy-light transition moment mu(tr) approximate to 10(-8) GeV-1 allows their decay nu(h) -> nu i gamma with a lifetime around 10(-3) s. This type of electromagnetic couplings has been recently proposed to explain the excess of electron-like events in baseline experiments. We show that the production and decay of these heavy neutrinos would transport energy from the central regions of the star to distances d approximate to 400 km, providing a very efficient mechanism to enhance the supernova shock front and heat the material behind it.