Modeling Hybrid Stars in Quark-Hadron Approaches

TL;DR

This paper models hybrid stars using quark-hadron approaches to understand their structure and properties, constrained by recent neutron star mass measurements, especially the high-mass pulsar PSR J1614-2230.

Contribution

It introduces a hybrid star model incorporating hyperonic and quark matter, providing insights into dense matter properties constrained by recent observational data.

Findings

Mass-radius relations consistent with observed neutron star masses.

Constraints on exotic phases in neutron star cores.

Implications for dense matter equations of state.

Abstract

The study of neutron stars, or more general compact stars, is a topic of central interest in nuclear astrophysics. Furthermore, neutron stars serve as the only physical systems whose properties can be used to infer information on cold and dense matter at several times nuclear saturation density. Therefore, neutron star physics is ideally suited to complement the studies of ultra-relativistic heavy-ion collisions that sample strongly interacting matter at high temperature and relatively small net baryon density. In general, in order to pin down or at least constrain the properties of dense matter, accurate measurements of neutron star properties like masses, radii, rotational frequency, and cooling behavior are needed. Here, in relatively recent times the reliable mass determination of the pulsar PSR J1614-2230 of $M = 1.97 \pm 0.04 M_\odot$ has introduced an important benchmark for modeling stars and strongly interacting matter. It puts constraints on the structure of compact stars and possible exotic phases in the core of the stars as will be discussed in this article. In order to investigate this point we will consider a model for star matter that includes hyperonic and quark degrees of freedom, and present results for compact star properties in the following.