Effects of Fock term, tensor coupling and baryon structure variation on a neutron star

TL;DR

This paper investigates how Fock terms, tensor couplings, and baryon structure changes influence the equation of state and maximum mass of neutron stars using relativistic models, aligning with recent astronomical observations.

Contribution

It introduces the combined effects of Fock terms, tensor couplings, and baryon structure variation in neutron star modeling, providing more accurate mass predictions.

Findings

Maximum neutron star mass of ~2.0 solar masses achieved

Fock contribution and tensor coupling are crucial for large mass

Baryon structure variation enhances neutron star mass

Abstract

The equation of state for neutron matter is calculated within relativistic Hartree-Fock approximation. The tensor couplings of vector mesons to baryons are included, and the change of baryon internal structure in matter is also considered using the quark-meson coupling model. We obtain the maximum neutron-star mass of $\sim 2.0 M_\odot$, which is consistent with the recently observed, precise mass, $1.97\pm0.04 M_{\odot}$. The Fock contribution is very important and, in particular, the inclusion of tensor coupling is vital to obtain such large mass. The baryon structure variation in matter also enhances the mass of a neutron star.