Strangeness in the cores of neutron stars

TL;DR

This paper explores the potential presence of strange quarks in neutron star cores, analyzing hyperonic and deconfined quark matter models to satisfy recent mass constraints from observations.

Contribution

It introduces an extended relativistic mean-field model with hyperons and a NJL model for quark matter, assessing their compatibility with neutron star mass observations.

Findings

Hyperons can exist within the mass constraints.

Deconfined quark matter models can support high-mass neutron stars.

The models accommodate recent observational constraints.

Abstract

The measurement of the mass 1.97 +/- 0.04 M_sun for PSR J1614-2230 provides a new constraint on the equation of state and composition of matter at high densities. In this contribution we investigate the possibility that the dense cores of neutron stars could contain strange quarks either in a confined state (hyperonic matter) or in a deconfined one (strange quark matter) while fulfilling a set of constraints including the new maximum mass constraint. We account for the possible appearance of hyperons within an extended version of the density-dependent relativistic mean-field model, including the phi-meson interaction channel. Deconfined quark matter is described by the color superconducting three-flavor NJL model.