Thermal effects on nuclear symmetry energy with a momentum-dependent effective interaction

TL;DR

This paper investigates how thermal effects influence the nuclear symmetry energy at finite temperatures using a momentum-dependent interaction, with implications for supernova dynamics and neutron star properties.

Contribution

It provides a detailed calculation of the temperature-dependent symmetry energy, including kinetic and interaction parts, and constructs a temperature-dependent equation of state for beta-stable nuclear matter.

Findings

Symmetry energy varies with temperature and density.

Proton fraction and electron chemical potential are computed at various temperatures.

A temperature-dependent equation of state for neutron star matter is developed.

Abstract

The knowledge of the nuclear symmetry energy of hot neutron-rich matter is important for understanding the dynamical evolution of massive stars and the supernova explosion mechanisms. In particular, the electron capture rate on nuclei and/or free protons in presupernova explosions is especially sensitive to the symmetry energy at finite temperature. In view of the above, in the present work we calculate the symmetry energy as a function of the temperature for various values of the baryon density, by applying a momentum-dependent effective interaction. In addition to a previous work, the thermal effects are studied separately both in the kinetic part and the interaction part of the symmetry energy. We focus also on the calculations of the mean field potential, employed extensively in heavy ion reaction research, both for nuclear and pure neutron matter. The proton fraction and the electron chemical potential, which are crucial quantities for representing the thermal evolution of supernova and neutron stars, are calculated for various values of the temperature. Finally, we construct a temperature dependent equation of state of $\beta$-stable nuclear matter, the basic ingredient for the evaluation of the neutron star properties.