Recent thermodynamic results from lattice QCD analyzed within a quasi-particle model

Understand

The thermodynamic behavior of QCD matter at high temperature is currently studied by lattice QCD theory.

• The main features are the fast rise of the energy density $\epsilon$ around the critical temperature $T_c$ and the large trace anomaly of the energy momentum tensor $< \Theta_\mu^\mu >=\epsilon - 3 P$ which hints at a strongly interacting system.
• Such features can be accounted for by employing a massive quasi-particle model with a temperature-dependent bag constant.
• Recent lattice QCD calculations with physical quark masses by the Wuppertal-Budapest group have shown a slower increase of $\epsilon$ and a smaller $<\Theta_\mu^\mu>$ peak with respect to previous results from the hotQCD collaboration.