In this paper, incorporating the property of the vacuum negative pressure, namely, the bag constant, we present 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 et al.’s EOS and SQM1 model, one finds that our EOS is softer than Fraga et al.’s EOS and SQM1 model. The reason for this difference is analyzed. With these results we investigate the structure of a quark star. A comparison between our model of the quark star and other models is made. The obtained mass of the quark star is $1.3\sim 1.66M_{\odot }$ and the radius is $9.5\sim 14\mathrm{Km}$. One can see that our star’s compactness is smaller than that of the other two models.

• Received 15 July 2010

DOI:https://doi.org/10.1103/PhysRevD.82.065017