Transport coefficients of the QGP

Abstract

The FASTSUM collaboration presents a study on the temperature dependence of the electrical conductivity $\sigma$ in the quark-gluon plasma, using the methods of lattice QCD. Correlators of the exactly conserved vector current are measured at different temperatures across the deconfinement transition, using ensembles of $2+1$ flavours of dynamical fermions on anisotropic lattices. We then employ bayesian methods (MEM) to extract the relevant spectral functions, which are found to be consistent with $\sigma/T$ rising as a function of $T$. The robustness of the results is verified by a detailed analysis of the systematics involved in the bayesian reconstruction of the spectral functions.