The effect of a density dependent bag constant on the structure of hot neutron star with a quark core

TL;DR

This study investigates how a density-dependent bag constant influences the structure of hot neutron stars with quark cores, revealing that it results in higher mass and smaller radius compared to a fixed bag constant.

Contribution

It introduces a density-dependent bag constant based on CERN SPS experimental results into neutron star modeling, improving the understanding of star structure with quark matter.

Findings

Density-dependent bag constant increases neutron star mass.

It decreases the star's radius compared to fixed bag constant models.

The model aligns with recent experimental data on quark-gluon plasma.

Abstract

As we go from center toward the surface of a neutron star, the state of baryonic matter changes from the de-confined quark-gluon to a mixed phase of quark and hadronic matter, and a thin crust of hadronic matter. For the quark matter, within MIT bag model, the total energy density of the system is the kinetic energy for non-interacting quarks plus a bag constant. In this article first we have considered a density dependent bag constant obtained using the recent experimental results of CERN SPS on the formation of a quark-gluon plasma. For calculations of the hadron phase, we use the lowest order constrained variational method. The equation of state of mixed phase has been determined using Gibbs conditions. Finally, we have calculated the structure of a hot neutron star with quark core employing TOV equation. Our results show that a density dependent bag constant leads to a higher mass and lower radius for the hot neutron star with respect to the case in which we use a fixed bag constant.