Charged-current neutrino opacity within the relativistic Hartree-Fock framework for astrophysical simulations of core-collapse supernovae and binary neutron star mergers

TL;DR

This paper improves the modeling of neutrino interactions in astrophysical events by incorporating momentum-dependent nuclear interactions using the relativistic Hartree-Fock framework, leading to significant differences from previous models.

Contribution

It introduces the relativistic Hartree-Fock approach for calculating charged-current neutrino opacities with momentum-dependent nuclear interactions in astrophysical simulations.

Findings

Large discrepancies in weak rates compared to RMF models

Substantial shift in medium-dependent modifications

Enhanced accuracy in neutrino flux predictions

Abstract

Neutrinos and their weak interactions play a vital role in the physics of core-collapse supernovae and binary neutron star mergers. Their description within astrophysical simulations, including the weak rates, is of pivotal importance not only for the prediction of accurate neutrino fluxes and spectra, including the associated conditions relevant to nucleosynthesis, neutrinos are also responsible for heating and cooling of the stellar plasma as well as the transport of lepton number and entropy. In the present article, we develop an essential improvement of the description of the underlying nuclear medium, necessary for the calculations of charged-current weak rates, with the inclusion of explicitly momentum-dependent nuclear interactions. To this end, we introduce the relativistic Hartree-Fock (RHF) approach and the associated momentum-dependent nucleon self-energies. We discuss the resulting neutrino and antineutrino opacities and find large discrepancies comparing the weak rates at the RHF level with those of commonly used relativistic mean-field (RMF) models; in particular, we observe a substantial shift of previously reported large medium-dependent modifications associated with the RMF approach.