Wilson Loop in Classical Lattice Gauge Theory and the Thermal Width of Heavy Quarkonium

Abstract

We present an estimate for the imaginary part of the recently introduced finite temperature real-time static potential. It can be extracted from the time evolution of the Wilson loop in classical lattice gauge theory. The real-time static potential determines, through a Schroedinger-type equation and a subsequent Fourier-transform of its solution, the spectral function of heavy quarkonium in finite-temperature QCD. We also compare the results of the classical simulations with those of Hard Thermal Loop improved simulations, as well as with analytic expectations based on resummed perturbation theory.