QCD plasma equilibration, elliptic flow and jet-quenching - phenomena of common origin

TL;DR

This paper explains the phenomena of rapid thermalization, elliptic flow, and jet-quenching in QCD matter at RHIC as arising from perturbative QCD interactions modeled by the BAMPS parton cascade, with results matching experimental data.

Contribution

It demonstrates that pQCD interactions within BAMPS can simultaneously explain thermalization, flow, and jet-quenching phenomena in heavy-ion collisions.

Findings

Shear viscosity to entropy ratio between 0.08 and 0.15.

Good agreement of flow parameter v_2 with experimental data.

Gluonic contribution significantly affects nuclear modification factor R_AA.

Abstract

Fast thermalization, a subsequent strong buildup of elliptic flow of QCD matter and jet-quenching as found at the Relativistic Heavy Ion Collider (RHIC) are understood as the consequence of perturbative QCD (pQCD) interactions within the 3+1 dimensional parton cascade BAMPS. The main contributions stem from pQCD inspired bremsstrahlung. Comparisons to Au+Au data of the flow parameter v_2 as a function of participation number as well as the gluonic contribution to the nuclear modification factor R_AA for most central collisions are given. Also the shear viscosity to entropy ratio is dynamically extracted, which lies in the range of 0.08-0.15, depending on the chosen coupling constant.