Quark deconfinement transition in neutron stars with the field correlator method

TL;DR

This paper investigates the hadron-quark phase transition in neutron stars using the field correlator method, linking QCD lattice results with astrophysical observations to constrain the properties of dense matter.

Contribution

It introduces an EOS for quark matter derived from the field correlator method and constrains it using neutron star mass measurements, connecting QCD calculations with astrophysical data.

Findings

Gluon condensate G_2 values are consistent with lattice QCD results.

The FCM-based EOS can explain observed neutron star masses.

Constraints on the deconfinement transition from neutron star data.

Abstract

A phase of strong interacting matter with deconfined quarks is expected in the core of massive neutron stars. In this article, we perform a study of the hadron-quark phase transition in cold (T = 0) neutron star matter and we calculate various structural properties of hybrid stars. For the quark phase, we make use of an equation of state (EOS) derived with the field correlator method (FCM) recently extended to the case of nonzero baryon density. For the hadronic phase, we consider both pure nucleonic and hyperonic matter, and we derive the corresponding EOS within a relativistic mean field approach. We make use of measured neutron star masses, and particularly the mass $M = 1.97 \pm 0.04 \, M_\odot$ of PSR J1614 -2230 to constrain the values of the gluon condensate $G_2$, which is one of the EOS parameters within the FCM. We find that the values of $G_2$ extracted from the mass measurement of PSR J1614 -2230 are consistent with the values of the same quantity derived within the FCM from recent lattice QCD calculations of the deconfinement transition temperature at zero baryon chemical potential. The FCM thus provides a powerful tool to link numerical calculations of QCD on a space-time lattice with measured neutron star masses.