Nuclear Matter and Neutron stars in a Parity Doublet Model

TL;DR

This paper explores how a parity doublet model incorporating chiral symmetry affects nuclear matter and neutron star properties, showing good agreement with observed neutron star masses without optimizing parameters.

Contribution

It introduces a parity doublet model approach to nuclear matter and neutron stars, emphasizing parameter dependence over optimization.

Findings

Successfully describes ground state nuclear matter

Predicts neutron star masses consistent with observations

Highlights the role of chiral symmetry restoration

Abstract

We investigate the properties of isospin-symmetric nuclear matter and neutron stars in a chiral model approach adopting the SU(2) parity doublet formulation. This ansatz explicitly incorporates chiral symmetry restoration with the limit of degenerate masses of the nucleons and their parity partners. Instead of searching for an optimized parameter set we explore the general parameter dependence of nuclear matter and star properties in the model. We are able to get a good description of ground state nuclear matter as well as large values of mass for neutron stars in agreement with observation.