Simultaneous chiral symmetry restoration and deconfinement - Consequences for the QCD phase diagram

TL;DR

This paper extends the vBag quark matter model to finite temperatures and isospin asymmetry, ensuring chiral and deconfinement transitions coincide, with implications for the QCD phase diagram and neutron star physics.

Contribution

It introduces an extension of the vBag model that incorporates finite temperature and isospin effects, aligning chiral and deconfinement transitions based on a hadronic EoS.

Findings

Extended vBag model at finite T and isospin asymmetry

Chiral and deconfinement transitions coincide in the model

Implications for the QCD phase diagram and neutron stars

Abstract

For studies of quark matter in astrophysical scenarios the thermodynamic bag model (tdBag) is commonly employed. Although successful, it does not account for dynamical chiral symmetry breaking (D$\chi$SB) and repulsions due to the vector interaction which is crucial to explain recent observations of massive, two solar mass neutron stars. In Kl\"ahn & Fischer (2015) we developed the novel vBag quark matter model which takes these effects into account. This article extends vBag to finite temperatures and isospin asymmetry. Another particular feature of vBag is the determination of the deconfinement bag constant $B_{\rm dc}$ from a given hadronic equation of state (EoS) in order to ensure that chiral and deconfinement transitions coincide. We discuss consequences of this novel approach for the phase transition construction, the phase diagram, and implications for protoneutron stars.