New equations of state based on the liquid drop model of heavy nuclei and quantum approach to light nuclei for core-collapse supernova simulations

TL;DR

This paper develops new equations of state for baryons in supernova simulations by incorporating temperature-dependent nuclear models, shell effects, and quantum mass evaluations, improving the accuracy of nuclear abundances and thermodynamic properties.

Contribution

The paper introduces a revised liquid drop model with temperature dependence and quantum mass evaluations for light nuclei, extending previous models for supernova core simulations.

Findings

Heavy nuclei abundances are affected by shell effects and temperature-dependent energies.

Light nuclei abundances are modified by quantum mass evaluations, influencing supernova heating and cooling.

Changes in nuclear abundances impact electron capture and neutrino scattering rates.

Abstract

We construct new equations of state for baryons at sub-nuclear densities for the use in core-collapse simulations of massive stars. The abundance of various nuclei is obtained together with thermodynamic quantities. A model free energy is constructed, based on the relativistic mean field theory for nucleons and the mass formula for nuclei with the proton number up to ~ 1000. The formulation is an extension of the previous model, in which we adopted the liquid drop model to all nuclei under the nuclear statistical equilibrium. We reformulate the new liquid drop model so that the temperature dependences of bulk energies could be taken into account. Furthermore, we extend the region in the nuclear chart, in which shell affects are included, by using theoretical mass data in addition to experimental ones. We also adopt a quantum theoretical mass evaluation of light nuclei, which incorporates the Pauli- and self-energy shifts that are not included in the ordinary liquid drop model. The pasta phases for heavy nuclei are taken into account in the same way as in the previous model. We find that the abundances of heavy nuclei are modified by the shell effects of nuclei and temperature dependence of bulk energies. These changes may have an important effect on the rates of electron captures and coherent neutrino scatterings on nuclei in supernova cores. The abundances of light nuclei are also modified by the new mass evaluation, which may affect the heating and cooling rates of supernova cores and shocked envelopes.