Neutron stars meet constraints from high and low energy nuclear physics

TL;DR

This paper introduces a new, thermodynamically consistent equation of state that models matter in neutron stars and heavy ion collisions, incorporating induced surface tension to address short-range repulsion.

Contribution

The novel equation of state includes induced surface tension and is applicable across a wide range of conditions, aligning with both nuclear physics experiments and astrophysical observations.

Findings

Reproduces properties of saturated nuclear matter

Aligns with proton flow constraints

Consistent with neutron star observational data

Abstract

A novel equation of state used for analysis of the heavy ion collision experimental data is generalized to also describe the matter inside neutron stars. This approach differs from others by including an induced surface tension caused by the short range repulsion between particles accounted by presence of their hard cores. This new equation of state respects thermodynamic consistency and is free from the usual causality problems. This makes it applicable over a wide range of temperatures and baryon densities, including the ones inside neutron stars. Despite small number of parameters the present equation of state reproduces properties of the saturated nuclear matter and is consistent with the proton flow constraint as well as with astrophysical data obtained from neutron star observations. Accordingly, we found the sets of parameters that agree with the same ones obtained from the heavy ion collision data analysis.