Nuclear Theory Group Seminar

Heavy Ion Collisions, Diffusion, AdS/CFT, and the Euclidean Lattice

Derek Teaney

Stony Brook University

To motivate this talk I first review the experimental data on Heavy Quark (HQ) Production and Flow at RHIC. These data suggest that the HQ diffusion coefficient is small. To constrain the diffusion coefficient it is natural to turn to the Euclidean Lattice. Using the Langevin equations of motion we analyze the HQ current-current correlator on the lattice and derive the spectral density. It is shown that to leading order in T/M the lattice correlator is independent of the HQ diffusion coefficient due to a sum rule. At subleading level the correlator does depend on the heavy quark relaxation time. At least parametrically, we outline a procedure to separate the transport contribution to the lattice correlator from the other continuum contributions. Finally, using the AdS/CFT correspondence we compute the spectral density of stress energy tensor correlations in strongly coupled N=4 SYM and compare it to perturbation theory. Although the spectral densities are markedly different at small ω, on the Lattice the free and strongly coupled correlation functions differ by less than 10%.