Elliptic flow and incomplete equilibration

Abstract

The dependence of eccentricity scaled elliptic flow on the partonic cross section in $\mathrm{Au}+\mathrm{Au}$ collisions at relativistic heavy ion collider (RHIC) energy $\sqrt{{s}_{\mathit{NN}}}=200 \mathrm{GeV}$ with impact parameter $b=8 \mathrm{fm}$ is analyzed using a multiphase transport (AMPT) model. It is shown that the dependence of eccentricity scaled elliptic flow on the partonic cross section could be described well by a formula suggested by Bhalerao et al. The eccentricity scaled elliptic flow of the parton is $19%~27%$ lower than its `hydrodynamic limit.' The hadronization of the parton through coalescence and hadronic dynamics (decay, collision) could influence the obtained deviation of eccentricity scaled elliptic flow of the hadron from its `hydrodynamic limit.' The hadronic final state interactions and hadronization reduce the extracted `hydrodynamic limit' by 20% and also reduce the deviation from the `hydrodynamic limit' by 26%.