QCD in neutron stars and strange stars

TL;DR

This paper reviews how Quantum Chromo Dynamics (QCD) influences the structure and possible states of matter in neutron stars and strange stars, including the potential existence of strange quark matter and related astrophysical objects.

Contribution

It provides a comprehensive overview of QCD's role in neutron star and strange star physics, highlighting theoretical possibilities of quark matter and observational implications.

Findings

Possible presence of unconfined quarks in neutron star cores

Theoretical stability of strange quark matter over atomic nuclei

Existence of self-bound strange quark stars and nuggets

Abstract

This paper provides an overview of the possible role of Quantum Chromo Dynamics (QDC) for neutron stars and strange stars. The fundamental degrees of freedom of QCD are quarks, which may exist as unconfined (color superconducting) particles in the cores of neutron stars. There is also the theoretical possibility that a significantly large number of up, down, and strange quarks may settle down in a new state of matter known as strange quark matter, which, by hypothesis, could be more stable than atomic nuclei. In the latter case new classes of self-bound, color superconducting objects, ranging from strange quark nuggets to strange quark stars, should exist. The properties of such objects will be reviewed along with the possible existence of deconfined quarks in neutron stars. Implications for observational astrophysics are pointed out.