Quark susceptibilities, transport properties and heavy quark production in an extended Quasi-Particle Model with N_f = 2 + 1 + 1 flavors

¹ Department of Physics and Astronomy ’E. Majorana’, University of Catania, Via S. Sofia 64, 1-95123 Catania, Italy
² Laboratori Nazionali del Sud, INFN-LNS, Via S. Sofia 62, 1-95123 Catania, Italy

^* e-mail: sambataro@lns.infn.it

Published online: 1 March 2023

Abstract

The quark susceptibilities are a very useful tool to understand the nature of the degrees of freedom in the vicinity of the QCD phase transition while Heavy-Quarks (HQs) transport coefficients give us information on their thermalization time in the Quark-Gluon Plasma (QGP). Recently, new lattice results for the equation of state of QCD with 2 + 1 + 1 dynamical flavors have become available. Therefore, we extend our QPM approach for N_f = 2 + 1 to N_f = 2 + 1 + 1 where the charm quark is included. We also explore the extension of QPM approach to a more realistic model in which partonic propagators explicitly depend on the three-momentum with respect to the partonic matter at rest in order to match pQCD at high momenta following Dyson-Schwinger studies in the vacuum. In this context, we evaluate and correctly reproduce both EoS and quark susceptibilities which are understimated in the simple QPM approach. Therefore, we study the impact of the extended QPM approach on the spatial diffusion coefficient D_s of charm quark making a comparison with the results in the standard QPM approach.