Shear viscosity of the quark-gluon plasma in a kinetic theory approach

Journal Article · Fri May 09 00:00:00 EDT 2014 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4875318· OSTI ID:22280396

Puglisi, A.; Plumari, S.; Scardina, F.; Greco, V. ^[1]

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1. Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, I-95125 Catania, Italy and Laboratorio Nazionale del Sud, INFN-LNS, Via S. Sofia 63, I-95125 Catania (Italy)

One of the main results of heavy ions collision (HIC) at relativistic energy experiments is the very small shear viscosity to entropy density ratio of the Quark-Gluon Plasma, close to the conjectured lower bound η/s=1/4π for systems in the infinite coupling limit. Transport coefficients like shear viscosity are responsible of non-equilibrium properties of a system: Green-Kubo relations give us an exact expression to compute these coefficients. We compute shear viscosity numerically using Green-Kubo relation in the framework of Kinetic Theory solving the relativistic transport Boltzmann equation in a finite box with periodic boundary conditions. We investigate a system of particles interacting via anisotropic and energy dependent cross-section in the range of temperature of interest for HIC. Green-Kubo results are in agreement with Chapman-Enskog approximation while Relaxation Time approximation can underestimates the viscosity of a factor 2. The correct analytic formula for shear viscosity can be used to develop a transport theory with a fixed η/s and have a comparison with physical observables like elliptic flow.

• OSTI ID: 22280396
• Journal Information: AIP Conference Proceedings, Vol. 1595, Issue 1; Conference: 7. European summer school on experimental nuclear astrophysics, Santa Tecla, Sicily (Italy), 15-17 Sep 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ANISOTROPY
APPROXIMATIONS
BOLTZMANN EQUATION
BOUNDARY CONDITIONS
COMPARATIVE EVALUATIONS
COUPLING
CROSS SECTIONS
DENSITY
ENERGY DEPENDENCE
ENTROPY
HEAVY ION REACTIONS
HYDRODYNAMIC MODEL
PERIODICITY
QUARK MATTER
RELATIVISTIC RANGE
RELAXATION TIME
SHEAR
TRANSPORT THEORY
VISCOSITY