# Quark matter symmetry energy effect on equation of state for neutron stars

## TL;DR

This paper investigates how isovector-vector couplings in quark matter influence the equation of state of neutron-star matter, highlighting their role in increasing symmetry energies and affecting neutron star properties.

## Contribution

It introduces a combined relativistic mean-field and Nambu-Jona-Lasinio model approach to study the impact of vector couplings on neutron star matter's symmetry energy.

## Key findings

- Isovector-vector couplings increase symmetry energy in quark matter.
- Hypercharge-vector couplings enhance hypercharge symmetry energy.
- Deconfinement transition modeled under Gibbs phase equilibrium.

## Abstract

We study the equation of state of neutron-star matter including the effects of isovector-vector coupling in quark matter. We employ the relativistic mean-field theory with an extended TM1 parameter set to describe hadronic matter and the SU(3) Nambu-Jona-Lasinio model with isovector-vector and hypercharge-vector couplings to describe the quark matter. The deconfinement hadron-quark phase transition is constructed under Gibbs phase equilibrium conditions. It is found that the isovector-vector and hypercharge-vector couplings in quark matter enhance the symmetry energy and hypercharge symmetry energy in neutron-star matter.