Isospin- and momentum-dependent effective interactions for the baryon octet and the properties of hybrid stars

TL;DR

This paper extends the MDI interaction model to include hyperon interactions and applies it to study the equation of state of hypernuclear matter and the properties of hybrid stars, considering phase transitions and interaction effects.

Contribution

The paper introduces an extended MDI interaction model for hyperon interactions and explores its implications for hybrid star properties and phase transitions.

Findings

Hyperon interactions significantly affect hybrid star mass and radius.

Attractive and repulsive ΣN interactions influence the equation of state.

Symmetry energy variations impact star stability and composition.

Abstract

The isospin- and momentum-dependent MDI interaction, which has been extensively used in intermediate-energy heavy-ion reactions to study the properties of asymmetric nuclear matter, is extended to include the nucleon-hyperon and hyperon-hyperon interactions by assuming same density, momentum and isospin dependence as for the nucleon-nucleon interaction. The parameters in these interactions are determined from the empirical hyperon single-particle potentials in symmetric nuclear matter at saturation density. The extended MDI interaction is then used to study in the mean-field approximation the equation of state of hypernuclear matter and also the properties of hybrid stars by including the phase transition from the hypernuclear matter to the quark matter at high densities. In particular, the effects of attractive and repulsive $\Sigma$N interactions and different values of symmetry energies on the hybrid star properties are investigated.