# Studies of the hybrid star structure within 2+1 flavors NJL model

## TL;DR

This study uses a 2+1 flavors NJL model with proper-time regularization to analyze hybrid star structures, finding consistent maximum masses aligned with recent astrophysical observations.

## Contribution

It introduces a hybrid EOS construction within the 2+1 flavors NJL model using proper-time regularization and compares different parameter sets for star structure predictions.

## Key findings

- Maximum hybrid star masses are similar across different parameter sets.
- Results agree with recent astrophysical observations of massive pulsars.
- Hybrid EOSs constructed show stable star configurations.

## Abstract

In this paper we use the equation of state (EOS) of 2+1 flavors Nambu-Jona-Lasinio (NJL) model to study the structure of compact stars. To avoid the ultraviolet divergence, we employ the proper-time regularization (PTR) with an ultraviolet cutoff. For comparison, we fix three sets of parameters, where the constraints of chemical equilibrium and electric charge neutrality conditions are taken into consideration. With a certain interpolation method in the crossover region, we construct three corresponding hybrid EOSs but find that the maximum masses of hybrid stars in the three different cases don't differ too much. It should be pointed out that, the results we get are in accordance with the recent astro-observation PSR J0348+0432, PSR J1614-2230, PSR J1946+3417.