Quark number susceptibilities from HTL-resummed thermodynamics

Abstract

We compute analytically the diagonal quark number susceptibilities for a quark-gluon 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 5 $T_c$, 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 ${\alpha }_s^3\log (1/{\alpha }_s)$, 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.

Comments: 13 pages, 5 figures, uses elsart.cls; v2: minor corrections; v3: sign in eq.(1) corrected