Relativistic mean field model for ultra-compact low mass neutron star of HESS J1731-347

TL;DR

This paper introduces a relativistic mean field model with meson crossing terms to explain the existence of ultra-compact, low-mass neutron stars like HESS J1731-347, aligning with recent astrophysical constraints.

Contribution

The model incorporates meson crossing interactions that significantly influence the symmetry energy, enabling it to match recent observational constraints for compact neutron stars.

Findings

Model successfully explains small neutron star radii.

Aligns with NICER and GW170817 observational data.

Supports the existence of ultra-compact low-mass neutron stars.

Abstract

The recent observation of the object HESS J1731-347 suggests the existence of a very light and very compact neutron star being a challenge for commonly used equation of state for dense matter. In this work we present a relativistic mean field model enriched with meson crossing terms among isovector and isoscalar mesons. Such interactions particularly dominate the behavior of the symmetry energy and accounts for small size of compact star radius. The proposed model fulfill the recent constraints concerning the symmetry energy slope and state-of-the-art compact stars constraints derived from the NICER measurements of PSR J0030+0451 and PSR J0740+6620 pulsars as well as from the GW170817 event and its associated electromagnetic counterparts AT2017gfo/GRB170817A.