Calculating Jet $v_n$ and the Event Plane in the Presence of a Jet

TL;DR

This paper introduces a method to accurately calculate jet flow harmonics and the event plane in heavy ion collisions, accounting for biases introduced by the jet itself, thereby improving the analysis of jet-medium interactions.

Contribution

It presents a novel approach to unbiasedly determine jet $v_n$ and the event plane using full jet reconstruction data.

Findings

Method reduces bias in jet $v_2$ measurement.

Enables more accurate studies of jet-medium interactions.

Improves understanding of medium-induced jet modifications.

Abstract

Advances in measurements of jets and collective phenomena in ultrarelativistic heavy ion collisions have led to further understanding of the properties of the medium created in such collisions. Measurements of the correlations between the axes of reconstructed jets and the reaction plane or second-order participant plane of the bulk medium (defined as jet $v_2$), as well as the higher-order participant planes (jet $v_n$), provide information on medium-induced parton energy loss. Additionally, knowledge of jet $v_n$ as well as the ability to reconstruct the event plane in the presence of a jet are necessary in analyses of jet-triggered particle correlations, which are used to study medium-induced jet shape modification. However, the presence of a jet can bias the event plane calculation, leading to an overestimation of jet $v_2$. This paper proposes a method for calculating jet $v_2$ (and by extension, the higher jet $v_n$ harmonics) and the event plane in an unbiased way, using knowledge of the azimuthal angle of the jet axis from full jet reconstruction.