Elliptic flow and shear viscosity of the shattered color glass condensate

14th Conference on Theoretical Nuclear Physics in Italy

Ruggieri, Marco^1 ; Scardina, Francesco^1,2 ; Plumari, Salvatore^1,2 ; Greco, Vincenzo^1,2

Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, I-95125 Catania, Italy^1

INFN-Laboratori Nazionali Del Sud, Via S. Sofia 62, I-95123 Catania, Italy^2

关键词: Color glass condensates;    Entropy density;    Non equilibrium;    Out of equilibrium;    Parton distribution functions;    Quark-gluon plasma;    Relativistic heavy ion collision;    Thermalization process;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/527/1/012018/pdf
DOI  :  10.1088/1742-6596/527/1/012018

来源: IOP

【 摘 要 】

In this contribution, we report on our results about the computation of the elliptic flow of the quark-gluon-plasma produced in relativistic heavy ion collisions, simulating the expansion of the fireball by solving the relativistic Boltzmann equation for the parton distribution function tuned at a fixed shear viscosity to entropy density ratio η/s. We emphasize the role of saturation in the initial gluon spectrum modelling the shattering of the color glass condensate, causing the initial distribution to be out of equilibrium. We find that the saturation reduces the efficiency in building-up the elliptic flow, even if the thermalization process is quite fast τtherm0.8fm/c. and the pressure isotropization even faster τisotr0.3fm/c. The impact of the initial non-equilibrium manifests for non-central collisions and can modify the estimate of the viscosity respect to the assumption of full thermalization in pT-space.