A dynamical quasiparticle approach for the QGP bulk and transport properties

The properties of quantum chromodynamics (QCD) nowadays are accessible by lattice QCD calculations at vanishing quark chemical potential μq = 0, but often lack a transparent physical interpretation. In this review, we report about results from an extended dynamical quasiparticle model (DQPM∗) in which the effective parton propagators have a complex self-energy that depends on the temperature T of the medium as well as on the chemical potential μq and the parton three-momentum p with respect to the medium at rest. It is demonstrated that this approach allows for a good description of QCD thermodynamics with respect to the entropy density, pressure, etc. above the critical temperature Tc ≈ 158 MeV. Furthermore, the quark susceptibility χq and the quark number density nq are found to be reproduced simultaneously at zero and finite quark chemical potential. The shear and bulk viscosities η,ζ, and the electric conductivity σe from the DQPM∗ also turn out in close agreement with lattice results for μq =0. The DQPM∗, furthermore, allows to evaluate the momentum p, T and μq dependencies of the partonic degrees of freedom also for larger μq which are mandatory for transport studies of heavy-ion collisions in the regime 5GeV < sNN < 10GeV. We finally calculate the charm quark diffusion coefficient Ds – evaluated from the differential cross-sections of partons in the medium for light and heavy quarks by employing the propagators and couplings from the DQPM – and compare it to the available lattice data. It is argued that the complete set of observables allows for a transparent interpretation of the properties of hot QCD.