Modeling early time dynamics of relativistic heavy ion collisions

FAIRNESS 2016

Oliva, Lucia^1,2 ; Ruggieri, Marco^1,3 ; Puglisi, Armando^1,2 ; Plumari, Salvatore^1,2 ; Scardina, Francesco^1,2 ; Coci, Gabriele^1,2 ; Greco, Vincenzo^1,2

Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, Catania

95123, Italy^1

INFN-Laboratori Nazionali Del Sud, Via S. Sofia 62, Catania

95123, Italy^2

College of Physics, University of Chinese Academy of Sciences, Yuquanlu 19A, Beijing

100049, China^3

关键词: Dynamical evolution;    Particles system;    Quark-gluon plasma;    Relativistic heavy ion collision;    Self-consistent calculation;    Thermalization time;    Transport theory;    Transverse pressure;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/742/1/012024/pdf
DOI  :  10.1088/1742-6596/742/1/012024

来源: IOP

【 摘 要 】

We studied isotropization and thermalization of the quark-gluon plasma produced by decaying color-electric flux tubes created at the very early stages of relativistic heavy ion collisions. We coupled the dynamical evolution of the initial field, which decays to a plasma by the Schwinger mechanism, to the dynamics of the many particles system produced by the decay. The evolution of such a system is described by relativistic transport theory at fixed values of the viscosity over entropy density ratio. Within a single self-consistent calculation scheme we computed quantities which serve as indicators of the equilibration of the plasma for a 1+1 dimensional expanding geometry. We find that the initial color-electric field decays within 1 fm/c and particles production occurs in less than 1 fm/c; however, in the case of large viscosity oscillations of the field appear along the entire time evolution of the system, affecting also the behaviour of the ratio between longitudinal and transverse pressure. In case of small viscosity we find that the isotropization time is about 0.8 fm/c and the thermalization time is about 1 fm/c, in agreement with the common lore of hydrodynamic approaches.