Speaker
Dr
Alexander Rothkopf
(Institute for Theoretical Physics, Heidelberg University)
Description
We present the latest results from two projects focused on determining the temperature dependence of the heavy quark potential from lattice QCD. The real and imaginary part of this real-time potential is obtained from the position and width of the lowest lying peak in the Coulomb gauge Wilson line correlator spectral function [1]. Spectral information is extracted from Euclidean time data using a novel Bayesian approach different from the Maximum Entropy Method, which has been shown to be capable of reproducing the relevant spectral features in mock data tests [2].
Since the determination of the imaginary part is related to the extraction of a spectral width, a large N_\tau is required for a reliable result. Hence the first project deploys anisotropic quenched lattices 32^3xN_\tau (b=7.0 x=3.5) with N_\tau=24,32,40,48,56,64,72,80,96, corresponding to 838.8MeV \geq T\geq 209.7MeV [3]. We find that fits to the Debye mass are in good agreement with prediction from HTL perturbation theory even at rather low temperatures T\gtrsim T_C.
The second project provides for the first time a Bayesian spectral function based determination of the heavy quark potential in dynamical lattice QCD [4]. We use the isotropic Nf=2+1 48^3x12 ASQTAD lattices of the HotQCD collaboration [5] and find a clean transition from a confining to a Debye screened Re[V], while the small Nt precludes us from making a quantitative statement about Im[V]. Close agreement between the real part of the potential and the color singlet free energies at high temperatures or small distances is observed.
[1] A.R., T. Hatsuda, S. Sasaki Phys.Rev.Lett. 108 (2012) 162001
[2] Y.Burnier, A.R. Phys.Rev.Lett. 111 (2013) 18, 182003
[3] Y. Burnier, A.R. in preparation
[4] O. Kaczmarek, A.R. in preparation
[5] A.Bazavov et al. PRD85(2010)074501
Primary authors
Dr
Alexander Rothkopf
(Institute for Theoretical Physics, Heidelberg University)
Dr
Olaf Kaczmarek
(University of Bielefeld, Department of Physics)
Dr
Yannis Burnier
(Ecole Polytechnique Federale de Lausanne - ITP)
