Equation of State of hot and dense QCD: Resummed perturbation theory confronts lattice data

Understand

We perform a detailed analysis of the predictions of resummed perturbation theory for the pressure and the second-, fourth-, and sixth-order diagonal quark number susceptibilities in a hot and dense quark-gluon plasma.

• First, we present an exact one-loop calculation of the equation of state within hard-thermal-loop perturbation theory (HTLpt) and compare it to a previous one-loop HTLpt calculation that employed an expansion in the ratios of thermal masses and the temperature.
• We find that this expansion converges reasonably fast.
• We then perform a resummation of the existing four-loop weak coupling expression for the pressure, motivated by dimensional reduction.