Plasmons, plasminos and Landau damping in a quasiparticle model of the quark-gluon plasma

A phenomenological quasiparticle model is surveyed for 2+1 quark flavors and compared with recent lattice QCD results. Emphasis is devoted to the effects of plasmons, plasminos and Landau damping. It is shown that thermodynamic bulk quantities, known at zero chemical potential, can uniquely be mapped towards nonzero chemical potential by means of a thermodynamic consistency condition and a stationarity condition.Comment: Sep. 2007. 13 pp. Invited talk given at Zimanyi 75 Memorial Workshop on Hadronic and Quark Matter, Budapest, Hungary, 2-4 Jul. 2007; reviewed and published versio

Quasi-particle model of strongly interacting matter

The successful quasi-particle model is compared with recent lattice data of the coefficients in the Taylor series expansion of the excess pressure at finite temperature and baryon density. A chain of approximations, starting from QCD to arrive at the model expressions for the entropy density, is presented.Comment: Nov 2004. 4pp. Invited talk given at 8th International Conference on Strangeness in Quark Matter (SQM2004), Cape Town, South Africa, 15-20 Sep 200

Plasmons, plasminos and Landau damping in a quasiparticle model of the quark-gluon plasma

A phenomenological quasiparticle model is surveyed for 2+1 quark flavors and compared with recent lattice QCD results. Emphasis is devoted to the effects of plasmons, plasminos and Landau damping. It is shown that thermodynamic bulk quantities, known at zero chemical potential, can uniquely be mapped towards nonzero chemical potential by means of a thermodynamic consistency condition and a stationarity condition.Comment: Sep. 2007. 13 pp. Invited talk given at Zimanyi 75 Memorial Workshop on Hadronic and Quark Matter, Budapest, Hungary, 2-4 Jul. 2007; reviewed and published versio

Viscosities in the Gluon-Plasma within a Quasiparticle Model

A phenomenological quasiparticle model, featuring dynamically generated self-energies of excitation modes, successfully describes lattice QCD results relevant for the QCD equation of state and related quantities both at zero and non-zero net baryon density. Here, this model is extended to study bulk and shear viscosities of the gluon-plasma within an effective kinetic theory approach. In this way, the compatibility of the employed quasiparticle ansatz with the apparent low viscosities of the strongly coupled deconfined gluonic medium is shown.Comment: 4 pages, 1 figure. To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee, US

Shear and bulk viscosities of the gluon plasma in a quasiparticle description

Shear and bulk viscosities of deconfined gluonic matter are investigated within an effective kinetic theory by describing the strongly interacting medium phenomenologically in terms of quasiparticle excitations with medium-dependent self-energies. We show that the resulting transport coefficients reproduce the parametric dependencies on temperature and coupling obtained in perturbative QCD at large temperatures and small running coupling. The extrapolation into the non-perturbative regime results in a decreasing specific shear viscosity with decreasing temperature, exhibiting a minimum in the vicinity of the deconfinement transition, while the specific bulk viscosity is sizeable in this region falling off rapidly with increasing temperature. The temperature dependence of specific shear and bulk viscosities found within this quasiparticle description of the pure gluon plasma is in agreement with available lattice QCD results.Comment: Sep 2011. 24pp. 6 figures. revised journal versio

Radiative energy loss of relativistic charged particles in absorptive media

We determine the energy loss spectrum per time-interval of a relativistic charge traversing a dispersive medium. Polarization and absorption effects in the medium are modelled via a complex index of refraction. We find that the spectrum amplitude becomes exponentially damped due to absorption mechanisms. Taking explicitly the effect of multiple scatterings on the charge trajectory into account, we confirm results obtained in a previous work.Comment: 4 pages, Proceedings of the 5th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2012), 27 May - 1 June 2012, Cagliari, Ital