Neutron Star Properties in the Chiral Quark-Meson Coupling Model

TL;DR

This paper models neutron star properties using a chiral quark-meson coupling approach, incorporating hyperons and $\Delta$-isobars, and extends symmetry considerations to match observed massive pulsar data.

Contribution

It introduces a chiral quark-meson coupling model with extended SU(3) symmetry, successfully predicting neutron star masses consistent with recent observations.

Findings

Maximum neutron star mass reaches observed values (~2 M_sun).

Hyperons like $\Lambda$ and $\Xi$ are generated in the model.

$\Sigma$ and $\Delta$-isobars do not appear in the star.

Abstract

We study the properties of neutron star using the chiral quark-meson coupling model, in which the quark-quark hyperfine interaction due to the exchanges of gluon and pion based on chiral symmetry is considered. We also examine the effects of hyperons and $\Delta$-isobars in a neutron star. Extending the SU(6) spin-flavor symmetry to more general SU(3) flavor symmetry in the vector-meson couplings to baryons, the maximum mass of neutron star can reach the recently observed, massive pulsar mass, $1.97 \pm 0.04 M_{\odot}$. In this calculation, $\Lambda$ and $\Xi$ are generated in a neutron star, while $\Sigma$ and $\Delta$-isobars do not appear.