Orateur
Description
We study within the Parton-Hadron-String Dynamics (PHSD) transport approach the partonic sector by explicitly calculating the differential partonic scattering cross sections (and transport coefficients) as a function of temperature $T$ and baryon chemical potential $\mu_B$ based on the dynamical quasi-particle model (DQPM) that is matched to reproduce the equation of state of the partonic system above the deconfinement temperature $T_c$ from lattice QCD. We also illustrate the values of temperature and chemical potential which are probed in heavy-ion collisions as a function of time and rapidity. We find that hadronic observables from central A+A collisions in the energy range 5 GeV ≤ $\sqrt{s_{NN}}$ ≤ 200 GeV, including ($T,\mu_B$)-dependent cross sections and parton masses, do not differ very much from the ones obtained using a vanishing $\mu_B$ dynamics. The conditions to study the properties of the QGP phase are only fulfilled at high bombarding energies where $\mu_B$ is however rather low at midrapidity. On the other hand, with decreasing the bombarding energy and, thus, increasing $\mu_B$, the hadronic phase becomes dominant and accordingly, it would be difficult to extract signals from the partonic dynamics only based on "bulk" observables.
Choix de session parallèle | 1.3 Physique nucléaire: physique hadronique et QCD |
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