Susceptibilities and speed of sound from the Polyakov-Nambu-Jona-Lasinio model

Abstract

We present the Taylor expansion coefficients of the pressure in quark number chemical potential ${\ensuremath{\mu}}_{0}={\ensuremath{\mu}}_{B}/3={\ensuremath{\mu}}_{u}={\ensuremath{\mu}}_{d}$, for the strongly interacting matter as described by the Polyakov-Nambu-Jona-Lasinio (PNJL) model for two light degenerate flavors of quarks $u$ and $d$. The expansion has been done up to eighth order in ${\ensuremath{\mu}}_{0}$, and the results are consistent with recent estimates from Lattice. We have further obtained the specific heat ${C}_{V}$, squared speed of sound ${v}_{s}^{2}$, and the conformal measure $\mathcal{C}$.