Energy loss as the origin of an universal scaling law of the elliptic flow

TL;DR

This paper explains the universal scaling law of elliptic flow across different energies and collision types as a result of energy loss by partons interacting with the nuclear color field, matching experimental data.

Contribution

It introduces a novel explanation linking elliptic flow scaling to parton energy loss in the nuclear color field, extending understanding of flow phenomena.

Findings

Scaling curve matches all data across energies and centralities.

Energy loss accounts for the universal elliptic flow behavior.

Potential extensions to higher transverse momentum and different collision systems are discussed.

Abstract

It is shown that the excellent scaling of the elliptic flow found for all centralities, species and energies from RHIC to the LHC for $p_{T}$ less than the saturation momentum is a consequence of the energy lost by a parton interacting with the color field produced in a nucleus-nucleus collision. In particular, the deduced shape of the scaling curve describes correctly all the data. We discuss the possible extensions to higher $p_{T}$, proton-nucleus and proton-proton collisions as well as higher harmonics.