Quark number susceptibilities of hot QCD up to g6 ln g -: art. no. 074032

The pressure of hot QCD has recently been determined to the last perturbatively computable order g(6) ln g by Kajantie using three-dimensional effective theories. A similar method is applied here to the pressure in the presence of small but non-vanishing quark chemical potentials, and the result is used to derive the quark number susceptibilities in the limit mu=0. The diagonal quark number susceptibility of QCD with n(f) flavors of massless quarks is evaluated to order g(6) ln g and compared with recent lattice simulations. It is observed that the results qualitatively resemble the lattice ones, and that when combined with the fully perturbative but yet undetermined g(6) term they may well explain the behavior of the lattice data for a wide range of temperatures.