In this paper, we generalize the improved quasi-particle model proposed in J. Cao et al., [ Phys. Lett. B {\bf711}, 65 (2012)] from finite temperature and zero chemical potential to the case of finite chemical potential and zero temperature, and calculate the equation of state (EOS) for (2+1) flavor Quantum Chromodynamics (QCD) at zero temperature and high density. We first calculate the partition function at finite temperature and chemical potential, then go to the limit T=0 and obtain the equation of state (EOS) for cold and dense QCD, which is important for the study of neutron stars. Furthermore, we use this EOS to calculate the quark-number density, the energy density, the quark-number susceptibility and the speed of sound at zero temperature and finite chemical potential and compare our results with the corresponding ones in the existing literature.
@article{arxiv.1311.4017,
title = {A thermodynamically consistent quasi-particle model without density-dependent infinity of the vacuum zero point energy},
author = {Liu-jun Luo and Jing Cao and Yan Yan and Wei-Min Sun and Hong-Shi Zong},
journal= {arXiv preprint arXiv:1311.4017},
year = {2013}
}