Determination of the strength of the vector-type four-quark interaction in the entanglement Polyakov-extended Nambu-Jona-Lasino model

TL;DR

This paper determines the vector-type four-quark interaction strength in the EPNJL model using lattice QCD data, and explores its implications for the hadron-quark phase transition and neutron star properties.

Contribution

It provides a new estimate of the vector interaction strength in the EPNJL model based on lattice QCD results, impacting the understanding of dense matter in neutron stars.

Findings

The vector interaction strength is G_v=0.33 G_s.

Critical chemical potential at zero temperature is about 1.6 GeV.

Results support neutron star mass observations with quark-hadron hybrid models.

Abstract

We determine the strength $G_{\rm v}$ of the vector-type four-quark interaction in the entanglement Polyakov-extended Nambu-Jona-Lasinio (EPNJL) model from the results of recent lattice QCD simulations with two-flavor Wilson fermions. The quark-number density is normalized by the Stefan-Boltzmann limit for small baryon chemical potential $\mu$ and temperature $T$ higher than the pseudo-critical temperature $T_c$ of the deconfinement transition. The strength determined from the normalized quark-number density is $G_{\rm v}=0.33 G_{\rm s}$ for the strength $G_{\rm s}$ of the scalar-type four-quark interaction. We explore the hadron-quark phase transition in the $\mu$-$T$ plane, using the two-phase model consisting of the quantum hadrodynamics model for the hadron phase and the EPNJL model for the quark phase. When $G_{\rm v}=0.33 G_{\rm s}$, the critical baryon chemical potential of the transition at zero $T$ is $\mu_c \sim 1.6$ GeV that accounts for two solar mass measurements of neutron stars in the framework of the quark-hadron hybrid star model.