Revisiting the Equation of State of Hybrid Stars in the Dyson-Schwinger Equation Approach to QCD

TL;DR

This paper explores the equation of state for hybrid stars using the Dyson-Schwinger approach to QCD, demonstrating that a 3-window interpolation can produce sufficiently stiff EoS to support stars over 2 solar masses, addressing the hyperon puzzle.

Contribution

It introduces a novel application of the 3-window interpolation method with Dyson-Schwinger equations to model hybrid star matter, providing a solution to the hyperon puzzle.

Findings

The 3-window interpolation yields a stiff enough EoS for massive hybrid stars.

Hybrid star models can exceed 2 solar masses with this approach.

The study offers insights into the hadron-quark phase transition in compact stars.

Abstract

We investigate the equation of state(EoS) and the effect of the hadron-quark phase transition of strong interaction matter in compact stars. The hadron matter is described with the relativistic mean field theory,and the quark matter is described with the Dyson-Schwinger equation approach of QCD. The complete EoS of the hybrid star matter is constructed with not only the Gibbs construction but also the 3-window interpolation. The mass-radius relation of hybrid stars is also investigated. We find that, although the EoSs of both the hadron matter with hyperon and $\Delta$-baryon and the quark matter are generally softer than that of the nucleon matter, the 3-window interpolation construction may provide an EoS stiff enough for a hybrid star with mass exceeding 2$M_{\odot}^{}$ and, in turn, solve the so called "hyperon puzzle".