Hard-thermal-loop resummation of the free energy of a quark-gluon plasma

The quark contribution to the free energy of a hot quark-gluon plasma is calculated to leading order in hard-thermal-loop (HTL) perturbation theory. This method selectively resums higher order corrections associated with plasma effects, such as screening, quasiparticles, and Landau damping. Comparing to the weak-coupling expansion of QCD, the error in the one-loop HTL free energy is of order ${\alpha }_s,$ but the large ${\alpha }_s^{3/2}$ correction from QCD plasma effects is included exactly.