Constraining the high-density behavior of nuclear symmetry energy with direct Urca processes

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Boukari, Olfa, Malik, Tuhin, Rabhi, Aziz, Providência, Constança
Format: Preprint
Publié: 2024
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866929604899373056
author Boukari, Olfa
Malik, Tuhin
Rabhi, Aziz
Providência, Constança
author_facet Boukari, Olfa
Malik, Tuhin
Rabhi, Aziz
Providência, Constança
contents The density dependence of the symmetry energy in relativistic mean-field models with density dependent couplings is discussed in terms of the possible opening of nucleonic direct Urca processes inside neutron stars, which induce a very rapid cooling of the star. The modification of the parametrization of the isospin channel of two models, DD2 and DDMEX, keeping the same isoscalar properties is considered and the implications are discussed. Within the models discussed it is not possible the onset of nucleonic direct Urca processes in stars with a mass below $\sim1.6\,M_\odot$ if chiral effective field theory constraints for neutron matter are imposed. A Bayesian inference calculation confirms the low probability that nucleonic direct Urca processes occur inside stars with masses below 1.8$M_\odot$, considering the isoscalar channel of the equation of state described by DD2 or DDMEX and the same symmetry energy at saturation. The lowest masses allowing direct Urca processes are associated with a slope of the symmetry energy above $60$ MeV and most likely a positive symmetry energy incompressibility. It is shown that the parametrization of the isospin channel proposed destroys the correlation between symmetry energy slope and incompressibility previously identified in several works.
format Preprint
id arxiv_https___arxiv_org_abs_2407_04403
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Constraining the high-density behavior of nuclear symmetry energy with direct Urca processes
Boukari, Olfa
Malik, Tuhin
Rabhi, Aziz
Providência, Constança
Nuclear Theory
High Energy Astrophysical Phenomena
The density dependence of the symmetry energy in relativistic mean-field models with density dependent couplings is discussed in terms of the possible opening of nucleonic direct Urca processes inside neutron stars, which induce a very rapid cooling of the star. The modification of the parametrization of the isospin channel of two models, DD2 and DDMEX, keeping the same isoscalar properties is considered and the implications are discussed. Within the models discussed it is not possible the onset of nucleonic direct Urca processes in stars with a mass below $\sim1.6\,M_\odot$ if chiral effective field theory constraints for neutron matter are imposed. A Bayesian inference calculation confirms the low probability that nucleonic direct Urca processes occur inside stars with masses below 1.8$M_\odot$, considering the isoscalar channel of the equation of state described by DD2 or DDMEX and the same symmetry energy at saturation. The lowest masses allowing direct Urca processes are associated with a slope of the symmetry energy above $60$ MeV and most likely a positive symmetry energy incompressibility. It is shown that the parametrization of the isospin channel proposed destroys the correlation between symmetry energy slope and incompressibility previously identified in several works.
title Constraining the high-density behavior of nuclear symmetry energy with direct Urca processes
topic Nuclear Theory
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2407.04403