相关论文: Shear Viscosity of a Gluon Plasma in Perturbative …
The relation of the shear viscosity coefficient to the recently introduced transport rate is derived within relativistic kinetic theory. We calculate the shear viscosity over entropy ratio \eta/s for a gluon gas, which involves elastic gg->…
The leading order contribution to the shear and bulk viscosities, \eta and \zeta, of a gluon plasma in perturbative QCD includes the gg -> gg (22) process, gg <-> ggg (23) process and multiple scattering processes known as the…
The shear viscosity to entropy density ratio, \eta /s, characterizes how perfect a fluid is. We calculate the leading order \eta /s of a gluon plasma in perturbation using the kinetic theory. The leading order contribution only involves the…
The remarkably small shear viscosity to entropy density ratio $\eta/s < 0.5$ of the quark-gluon plasma (QGP) is a key insight from heavy ion experiments. Nonetheless, the basic understanding of this `observable' still seems to be…
We calculate the shear viscosity $\eta$ in the quark-gluon plasma (QGP) phase within a virial expansion approach with particular interest in the ratio of $\eta$ to the entropy density $s$, i.e. $\eta/s$. The virial expansion approach allows…
The shear viscosity of a gluon gas is calculated using the Green-Kubo relation. Time correlations of the energy-momentum tensor in thermal equilibrium are extracted from microscopic simulations using a parton cascade solving various…
We compute the shear viscosity of two-flavor QCD plasma in an external magnetic field in perturbative QCD at leading log order, assuming that the magnetic field is weak or soft: $eB\sim g^4\log(1/g)T^2$. We show that the shear viscosity…
Shear viscosity of the gluon plasma in SU(3) YM theory is calculated nonperturbatively, within the stochastic vacuum model. The result for the ratio of the shear viscosity to the entropy density, proportional to the squared chromo-magnetic…
We calculate the shear (eta) and bulk (zeta) viscosities of a weakly coupled quark gluon plasma at the leading-log order with finite temperature T and quark chemical potential mu. We find that the shear viscosity to entropy density ratio…
We investigate the temperature dependence of the shear viscosity ($\eta$) and bulk viscosity ($\zeta$) of the gluon plasma using lattice QCD over the range 0.76--2.25$\,T_c$, extending from below the transition temperature $T_c$ across the…
The transport coefficients of strongly interacting matter are currently subject of intense theoretical and phenomenological studies due to their relevance for the characterization of the quark-gluon plasma produced in ultra relativistic…
We argue that the phenomenologically inferred ratio of shear viscosity to entropy density of the quark-gluon plasma, $\eta/\s < 0.5$ near the deconfinement temperature $T_c$, can be understood from perturbative QCD. To rebut the widespread,…
The shear ($\eta$) and bulk ($\zeta$) viscous coefficients have been evaluated for a gluonic fluid. The elastic, $gg \rightarrow gg$ and the inelastic, number non-conserving, $gg\rightarrow ggg$ processes have been considered as the…
In recent years, there has been a significant effort to extract the temperature-dependent shear ($\eta/s$) and bulk ($\zeta/s$) viscosity over entropy ratios of the quark-gluon plasma from a global comparison of heavy-ion data with results…
We extract the shear viscosity to entropy density ratio \eta/s of cold fermionic atoms in the unitarity limit from experimental data on the damping of collective excitations. We find that near the critical temperature \eta/s is roughly…
The elliptic flow $v_2$ and the ratio of the shear viscosity over the entropy density, $\eta/s$, of gluon matter are calculated from the perturbative QCD (pQCD) based parton cascade Boltzmann approach of multiparton scatterings. For Au+Au…
Transport properties of the quark-gluon plasma are instrumental to testing perturbative quantum chromodynamics and understanding the extreme conditions of relativistic heavy-ion collisions. This study presents an analytical investigation of…
We consider QCD at temperatures T near Tc, where the theory deconfines. We distinguish between a "complete" Quark Gluon Plasma (QGP), where the vacuum expectation value of the renormalized Polyakov loop is near unity, essentially constant…
We derive an expression relating the transport parameter $\hat{q}$ and the shear viscosity $\eta$ of a weakly coupled quark-gluon plasma. A deviation from this relation can be regarded as a quantitative measure of ``strong coupling'' of the…
The shear viscosity to entropy density ratio ({\eta}/s) of quark gluon plasma produced in ultra- relativistic heavy-ion collisions has been studied from the energy loss of heavy quarks in QGP medium. We have also studied the bulk viscosity…