The study of Anisotropic Flows at LHC with purturbative simulation

TL;DR

This paper uses perturbative simulations to study anisotropic flow in heavy ion collisions at LHC, finding that nonperturbative effects are crucial to match experimental data.

Contribution

It introduces a perturbative Monte Carlo simulation of parton flows and highlights the limitations of purely perturbative approaches in explaining experimental results.

Findings

Perturbative simulation fails to reproduce RHIC and LHC flow data.

Nonperturbative effects are essential from the earliest collision stages.

Perturbative sector alone is insufficient to explain observed anisotropic flows.

Abstract

We study the harmonic flows, for example, the directed, elliptic, third and fourth flow of the system of partons formed just after relativistic heavy ion collisions. We calculate the minijets produced during the primary collisions using standard parton distributions for the incomming projectile and target nucleus. We solve the Boltzmann equations of motion for the system of minijets by Monte Carlo method within only the perturbative sector. Based on the flow data calculated, we conclude the simulation can not explain the experimental results at RHIC and LHC so that the nonperturbative sector plays much more important roles even from the earliest stage of heavy ion collisions.