Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Shear Viscosity in a Perturbative Quark-Gluon-Plasma   Among the key features of hot and dense QCD matter produced in
ultra-relativistic heavy-ion collisions at RHIC is its very low shear
viscosity, indicative of the properties of a near-ideal fluid, and a large
opacity demonstrated by jet energy loss measurements. In this work, we utilize
a microscopic transport model based on the Boltzmann equation with quark and
gluon degrees of freedom and cross sections calculated from perturbative
Quantum Chromodynamics to simulate an ideal Quark-Gluon-Plasma in full thermal
and chemical equilibrium. We then use the Kubo formalism to calculate the shear
viscosity to entropy density ratio of the medium as a function of temperature
and system composition. One of our key results is that the shear viscosity over
entropy-density ratio $\eta/s$ becomes invariant to the chemical composition of
the system when plotted as a function of energy-density instead of temperature.

19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph