Higher moments of charge fluctuations in QCD at high temperature

Abstract

We present lattice results for baryon number, strangeness and electric charge fluctuations as well as their correlations at finite temperature and vanishing chemical potentials, i.e. under conditions relevant for RHIC and LHC. We find that the fluctuations change rapidly at the transition temperature $T_c$ and approach the ideal quark gas limit already at approximately $1.5T_c$. This indicates that quarks are the relevant degrees of freedom that carry the quantum numbers of conserved charges at $T\ge 1.5T_c$. At low temperature, qualitative features of the lattice results are well described by a hadron resonance gas model.

Comments: 4 pages, 3 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee