Diagonal and off-diagonal density fluctuations in hot nuclear matter, and applications to neutrino transport in supernovae.

Abstract

We calculate the effects of interactions on the density fluctuations of an $n$, $p$, $e$ plasma. The scattering of neutrinos arising from the Fermi part of the neutral current interactions with protons, under supernova conditions, is practically extinguished by Coulomb effects in the plasma. Charged-current reactions are discussed in terms of off-diagonal density fluctuations. Inclusion of the symmetry energy term in the nuclear interaction gives rise to a large reduction in the Fermi part of the cross section for $\ensuremath{\nu}+n\ensuremath{\rightarrow}{e}^{\ensuremath{-}}+p$.