Microscopic calculations of neutrino scattering and absorption in warm dense nuclear matter

Speaker(s) Jeremy Holt

Please contact erule@berkeley.edu for zoom links.

Numerical simulations of core-collapse supernovae, proto-neutron star cooling, and neutron star mergers require modeling of neutrino scattering and reaction rates that are sensitive to medium effects, including nuclear mean fields and correlations. In the past, it has been found that nuclear mean fields play an especially important role for enhancing electron-neutrino absorption and suppressing antineutrino absorption in warm and neutron-rich nuclear matter. In the present study, we investigate nuclear correlations on equal footing to mean fields through the random phase approximation (RPA) computed from microscopic models of the nucleon-nucleon interaction derived from chiral effective field theory. We find that RPA calculations generically indicate the presence of nuclear collective modes, which at low neutrino energies tend to suppress neutrino absorption and enhance antineutrino absorption, opposite to the effect of mean fields. We conclude that nuclear correlations should be treated on a consistent footing with mean fields in deriving neutrino charged-current reaction cross sections for astrophysical simulations.