Bag model and quark star

TL;DR

This paper introduces a new equation of state model for quark matter incorporating vacuum negative pressure, and applies it to analyze quark star structures, resulting in predictions of lower compactness compared to other models.

Contribution

A novel EOS model for quark matter that includes vacuum negative pressure, used to study quark star properties and compare with existing models.

Findings

Quark star masses range from 1.3 to 1.66 solar masses.

Star radii are between 9.5 and 14 km.

Our model predicts less compact stars than other models.

Abstract

In this paper, incorporating the property of the vacuum negative pressure, namely, the bag constant, we presented a new model of the equation of state (EOS) of quark matter at finite chemical potential and zero temperature. By comparing our EOS with Fraga {\it et~al.}'s EOS and SQM1 model, one find that our EOS is softer than Fraga {\it et~al.}'s EOS and SQM1 model. The reason for this difference is analyzed. With these results we investigate the structure of quark star. A comparison between our model of quark star and other models is made. The obtained mass of quark star is $ 1.3 \sim 1.66 M_\odot$ and the radius is $9.5 \sim 14 Km$. One can see that our star's compactness is smaller than that of other two models.