Quark number susceptibilities from HTL-resummed thermodynamics

We compute analytically the diagonal quark number susceptibilities for a quarkgluon plasma at finite temperature and zero chemical potential, and compare with recent lattice results. The calculation uses the approximately self-consistent resummation of hard thermal and dense loops that we have developed previously. For temperatures between 1.5 to 5Tc , our results follow the same trend as the lattice data, but exceed them in magnitude by about 5− 10%. We also compute the lowest order contribution, of order αs log(1/αs), to the off-diagonal susceptibility. This contribution, which is not a part of our self-consistent calculation, is numerically small, but not small enough to be compatible with a recent lattice simulation.