Seminar in Hadronic Physics

Viscosity effects on quarkonium states in a deconfined QCD plasma

Adrian Dumitru

City University of New York & RIKEN BNL

In an expanding plasma, non-zero shear viscosity implies an anisotropic momentum distribution of particles in a fluid cell. This leads to anisotropic screening of static electric fields. I present a simple model for the static potential between infinitely heavy fundamental charges which includes the Coulomb as well as the string force and is easily extended to anisotropic plasmas. The dominant temperature and viscosity dependence of the QQ_bar binding energies is found to arise from a non-entropy like contribution to the free energy of a single heavy quark, which is absent in conformal theories. Finally, I show the binding energies of 1S/1P charmonium and bottomonium states and the polarization of 1P bb_bar states in the deconfined phase obtained from our model potential.