Heavy-quark effects on cold quark matter and self-bound stars

TL;DR

This paper uses perturbative QCD to study how heavy quarks influence the properties of cold, dense quark matter and explores the stability of hypothetical charm stars, concluding they are unstable.

Contribution

It provides a detailed analysis of heavy-quark effects on the equation of state and examines the stability of charm stars, a novel class of ultradense compact objects.

Findings

Heavy-quark effects significantly modify the equation of state.

Charm stars are found to be unstable under radial oscillations.

Abstract

Heavy-quark effects on the equation of state for cold and dense quark matter are obtained from perturbative QCD, yielding observables parametrized only by the renormalization scale. In particular, we investigate the thermodynamics of charm quark matter under the constraints of $\beta$ equilibrium and electric charge neutrality in a region of densities where perturbative QCD is, in principle, much more reliable. Finally, we analyze the stability of charm stars, a possible new branch of ultradense, self-bound compact stars, and find that they are unstable under radial oscillations.