Collective flow in single-hit QCD kinetic theory

Abstract

Motivated by recent interest in collectivity in small systems, we calculate the harmonic flow response to initial geometry deformations within weakly coupled QCD kinetic theory using the first correction to the free-streaming background. We derive a parametric scaling formula that relates harmonic flow in systems of different sizes and different generic initial gluon distributions. We comment on similarities and differences between the full QCD effective kinetic theory and the toy models used previously. Finally we calculate the centrality dependence of the integrated elliptic flow $v_2$ in oxygen-oxygen, proton-lead and proton-proton collision systems.

Comments: Published version. The following changes has been made: updated discussion in section 3.1 and plots of elliptic flow scaling. Added plots for triangular flow scaling. Revised section 3.3 with an improved procedure