Electrically charged strange stars with an interacting quark matter equation of state

L Lazzari,V P Gonçalves

doi:10.1103/physrevd.102.034031

Abstract

The properties of electrically charged strange quark stars predicted by an interacting quark matter equation of state (EoS) based on cold and dense perturbative quantum chromodynamics (pQCD) are investigated. The stability of strange stars is analyzed considering different models for the electric charge distribution inside the star as well as for distinct values for the total electric charge. A comparison with the predictions derived using the MIT bag model is also presented. We show that the presence of a net electric charge inside strange stars implies in a larger maximum mass in comparison to their neutral counterparts. Moreover, we demonstrate that the pQCD EoS implies larger values for the maximum mass of charged strange stars, with very heavy charged stars being stable systems against radial oscillations. For an electric charge distribution given by $q(r) = \beta r^3$, the pQCD EoS implies unstable configurations for large values of the renormalization scale as well as for large values of $\beta$, in contrast to the MIT bag model predictions.

Highlights

The description of matter at high densities and/or high temperatures is one of the main challenges of the strong interactions theory—quantum chromodynamics (QCD). (For a recent review see, e.g., Ref. [1].) While the regime of high temperatures and vanishing baryon density have been explored in heavy ion collisions at the RHIC and LHC, the QCD at high baryon densities and low temperatures is fundamental to determining the properties of compact stars [2], where the density of the matter is predicted to exceed the nuclear density matter and the system is expected to be described in terms of deconfined quark degrees of freedom
We have that the perturbative quantum chromodynamics (pQCD) equation of state (EoS) is strongly dependent on the renormalization scale, with the band representing the uncertainty associated to this scale
In this paper we have investigated, for the first time, the equilibrium and stability of charged strange stars considering the EoS derived in Ref. [19], which takes into account the interaction between quarks, and that have been derived using cold and dense perturbative QCD

Summary

Introduction

The description of matter at high densities and/or high temperatures is one of the main challenges of the strong interactions theory—quantum chromodynamics (QCD). (For a recent review see, e.g., Ref. [1].) While the regime of high temperatures and vanishing baryon density have been explored in heavy ion collisions at the RHIC and LHC, the QCD at high baryon densities and low temperatures is fundamental to determining the properties of compact stars [2], where the density of the matter is predicted to exceed the nuclear density matter and the system is expected to be described in terms of deconfined quark degrees of freedom. According to the Bodmer-Witten hypothesis [3,4], the absolute ground state for the hadronic matter is the strange quark matter (SQM) rather than 56Fe, which implies the possible existence of compact stars entirely made of deconfined up, down, and strange quarks, usually denoted strange quark stars (SQS) [5,6,7,8]. Another possibility is the presence of deconfined quark matter inside neutron stars (NSs), forming hybrid stars.

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Conclusion