Numerical study of the equation of state for two flavor QCD at non-zero baryon density

Abstract

We discuss the equation of state (EoS) for two flavor QCD at non-zero temperature and density. Derivatives of $\ln Z$ with respect to quark chemical potential $\hat{I}{¼}_q$ are calculated up to sixth order. From this Taylor series, the pressure, quark number density and associated susceptibilities are estimated as functions of temperature and $\hat{I}{¼}_q$. It is found that the fluctuations in the quark number density increase in the vicinity of the phase transition temperature and the susceptibilities start to develop a pronounced peak as $\hat{I}{¼}_q$ is increased. This suggests the presence of a critical endpoint in the $(\hat{I}{¼}_q,T)$ plane. Moreover, we comment on the hadron resonance gas model, which explains well our simulation results below $T_c$.

5 pages, 6 figures, Poster presented at SEWM 2004