Effect of mesonic off-shell correlations in the PNJL equation of state

TL;DR

This paper investigates how mesonic off-shell correlations influence the equation of state in the 2-flavor PNJL model, emphasizing the role of Landau damping and momentum dependence in mesonic contributions at finite temperature.

Contribution

It introduces a comprehensive analysis of meson contributions including full momentum dependence and Landau damping effects within the PNJL model, highlighting their impact on thermodynamic quantities.

Findings

Mesonic off-shell effects increase pressure above 0.8 T_c.

Landau damping significantly affects the mesonic pressure and trace anomaly.

Results depend on the Polyakov-loop potential parameter T_0.

Abstract

We study the meson contribution to the equation of state of the 2-flavor PNJL model, including the full momentum dependence of the meson polarization loops. Within the Beth-Uhlenbeck approach, we demonstrate that the contribution from the quark-antiquark continuum excitations in the spacelike region $\omega^2 - q^2 < 0$, i.e. the Landau damping, leads to an increase of the pressure for temperatures $\gtrsim 0.8\,T_c^\chi$ and a significant meson momentum cut-off dependence in the mesonic pressure and the QCD trace anomaly. We investigate the dependence of the results on the choice of the Polyakov-loop potential parameter $T_0$. From the dependence of the mesonic pressure on the current quark mass, by means of the Feynman-Hellmann theorem, we evaluate the contribution of the pion quasiparticle gas and Landau damping to the chiral condensate.