Stability of the $\beta$-equilibrated dense matter and core-crust transition in neutron stars

TL;DR

This paper investigates the stability of dense nuclear matter in neutron stars, focusing on the core-crust transition and how nuclear interactions influence neutron star properties, aligning with recent observational data.

Contribution

It introduces a density-dependent M3Y interaction model to analyze the core-crust transition and neutron star stability, providing new insights into the transition density and pressure.

Findings

Transition density: 0.0938 fm$^{-3}$

Transition pressure: 0.5006 MeV fm$^{-3}$

Proton fraction at transition: 0.0308

Abstract

The stability of the $\beta$-equilibrated dense nuclear matter is analyzed with respect to the thermodynamic stability conditions. Based on the density dependent M3Y effective nucleon-nucleon interaction, the effects of the nuclear incompressibility on the proton fraction in neutron stars and the location of the inner edge of their crusts and core-crust transition density and pressure are investigated. The high-density behavior of symmetric and asymmetric nuclear matter satisfies the constraints from the observed flow data of heavy-ion collisions. The neutron star properties studied using $\beta$-equilibrated neutron star matter obtained from this effective interaction for a pure hadronic model agree with the recent observations of the massive compact stars. The density, pressure and proton fraction at the inner edge separating the liquid core from the solid crust of neutron stars are determined to be $\rho_t=$ 0.0938 fm$^{-3}$, P$_t=$ 0.5006 MeV fm$^{-3}$ and x$_{p(t)}=$ 0.0308, respectively.