Heavy quark momentum diffusion coefficient during hydrodynamization via effective kinetic theory

¹ Institute for Theoretical Physics, Technische Universität Wien, 1040 Vienna, Austria
² Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
³ Department of Physics, University of Jyväskylä, P.O. Box 35, 40014 Finland
⁴ Helsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Finland

^* e-mail: jarkko.t.peuron@jyu.fi

Published online: 26 June 2024

Abstract

In these proceedings, we compute the heavy quark momentum diffusion coefficient using QCD effective kinetic theory for a plasma going through the bottom-up thermalization scenario until approximate hydrodynamization. This transport coefficient describes heavy quark momentum diffusion in the quark-gluon plasma and is used in many phenomenological frameworks, e.g. in the open quantum systems approach. Our extracted nonthermal diffusion coefficient matches the thermal one for the same energy density within 30%. At large occupation numbers in the earliest stage, the transverse diffusion coefficient dominates, while the longitudinal diffusion coefficient is larger for the underoccupied system in the later stage of hydrodynamization.