Origins of the di-jet asymmetry in heavy ion collisions

TL;DR

This paper investigates the origins of di-jet asymmetry in heavy ion collisions, revealing that fluctuations, energy loss, and path length differences contribute, with fluctuations being dominant.

Contribution

The study demonstrates that di-jet asymmetry primarily arises from fluctuations, with additional effects from energy loss and path length differences, using the extsc{Jewel} event generator.

Findings

Fluctuations dominate di-jet asymmetry in both proton-proton and heavy ion collisions.

Energy loss fluctuations significantly contribute to the asymmetry in heavy ion collisions.

Path length differences are a sub-leading effect in di-jet asymmetry.

Abstract

The di-jet asymmetry --- the measure of the momentum imbalance in a di-jet system --- is a key jet quenching observable. Using the event generator \jewel we show that the di-jet asymmetry is dominated by fluctuations both in proton-proton and in heavy ion collisions. We discuss how in proton-proton collisions the asymmetry is generated through recoil and out-of-cone radiation. In heavy ion collisions two additional sources contribute to the asymmetry, namely energy loss fluctuations and differences in path length. The latter is shown to be a sub-leading effect. We discuss the implications of our results for the interpretation of this observable.