Hyperon mixing and universal many-body repulsion in neutron stars

TL;DR

This paper introduces a universal many-body repulsion model for baryonic systems using multi-pomeron exchange potential, which helps explain neutron star properties including hyperon mixing effects and maximum mass.

Contribution

The paper develops a multi-pomeron exchange potential model for baryonic interactions, calibrated with nucleus-nucleus scattering data, and applies it to neutron star equations of state with hyperon mixing.

Findings

The MPP model reproduces experimental hyperon binding energies.

The neutron star maximum mass exceeds 2 solar masses with hyperon mixing.

The model aligns terrestrial experiments with astrophysical observations.

Abstract

A multi-pomeron exchange potential (MPP) is proposed as a model for the universal many-body repulsion in baryonic systems on the basis of the Extended Soft Core (ESC) bryon-baryon interaction. The strength of MPP is determined by analyzing the nucleus-nucleus scattering with the G-matrix folding model. The interaction in $\Lambda N$ channels is shown to reproduce well the experimental $\Lambda$ binding energies. The equation of state (EoS) in neutron matter with hyperon mixing is obtained including the MPP contribution, and mass-radius relations of neutron stars are derived. It is shown that the maximum mass can be larger than the observed one $2M_{\odot}$ even in the case of including hyperon mixing on the basis of model-parameters determined by terrestrial experiments.