Hybrid star structure with the Field Correlator Method

TL;DR

This paper investigates the structure of hybrid stars using the Field Correlator Method for quark matter, analyzing phase transitions, color-flavor locking, and hyperon effects on star properties.

Contribution

It introduces the application of the Field Correlator Method to model quark matter in hybrid stars, including color-flavor locking and hyperon effects, and confirms the CSS mapping in this context.

Findings

Phase transition features depend on $V_1$, $G_2$, and $\Delta$.

CSS mapping remains valid for paired quark matter.

Hyperons influence the mass-radius relation of hybrid stars.

Abstract

We explore the relevance of the color-flavor locking phase in the equation of state (EoS) built with the Field Correlator Method (FCM) for the description of the quark matter core of hybrid stars. For the hadronic phase, we use the microscopic Brueckner-Hartree-Fock (BHF) many-body theory, and its relativistic counterpart, i.e. the Dirac-Brueckner (DBHF). We find that the main features of the phase transition are directly related to the values of the quark-antiquark potential $V_1$, the gluon condensate $G_2$ and the color-flavor superconducting gap $\Delta$. We confirm that the mapping between the FCM and the CSS (constant speed of sound) parameterization holds true even in the case of paired quark matter. The inclusion of hyperons in the hadronic phase and its effect on the mass-radius relation of hybrid stars is also investigated.