Influence of hyperon-hyperon interaction on the properties of neutron stars

TL;DR

This paper investigates how hyperon-hyperon interactions influence neutron star properties using a covariant hadronic model and quark matter considerations, aligning predictions with recent astronomical observations.

Contribution

It introduces a detailed hyperon-hyperon interaction model with phenomenological constraints and explores its effects on neutron star structure and observable parameters.

Findings

Maximum neutron star mass exceeds two solar masses.

Model predictions agree with recent observational data.

Hyperon interactions significantly affect star properties.

Abstract

The properties of neutron stars are studied in a composite model of the strong interaction. In the regime of low to medium baryonic densities a covariant hadronic model is adopted which includes an exclusive channel for the hyperon-hyperon interaction mediated by hidden strangeness mesons, which in turn couple to other mesons through polynomial vertices. The new coupling constants are subject to phenomenological constraints. The presence of free quarks in the core of the star is considered by using the Nambu-Jona Lasinio model supplemented with a vector interaction. The deconfinement process is described by a continuous coexistence of phases. Several structure parameters of neutron stars, such as mass-radius relation, moment of inertia, tidal deformability, and the propagation of nonradial f and g-modes within the relativistic Cowling approximation are studied. The predictions of the model are in good agreement with recent observational data, in particular the maximum inertial mass is greater than the observational lower limit of two solar masses.