Jet Reconstruction with Particle Flow in Heavy-Ion Collisions with CMS

TL;DR

This paper discusses the adaptation of the particle flow algorithm for jet reconstruction in heavy-ion collisions at CMS, aiming to improve resolution and reduce uncertainties compared to calorimetric methods.

Contribution

The paper introduces an adaptation of the particle flow algorithm for heavy-ion collisions and evaluates its performance in PbPb events.

Findings

Improved jet energy resolution with particle flow in heavy-ion collisions.

Reduced systematic uncertainties in jet measurements.

Effective reconstruction of jets in PbPb collisions.

Abstract

In the particle-flow approach information from all available sub-detector systems is combined to reconstruct all stable particles. The global event reconstruction has been shown to improve, in particular, the resolution of jet energy and missing transverse energy in pp collisions compared to purely calorimetric measurements. This improvement is achieved primarily by combining the precise momentum determination of charged hadrons in the silicon tracker with the associated energy depositions in the calorimeters. By resolving individual particles inside jets, particle flow reduces the sensitivity of the jet energy scale to the jet fragmentation pattern, which is known to be one of the largest sources of systematic uncertainty in jet reconstruction. Particle flow reconstruction is thus potentially well-suited for the study of potential modifications to jet fragmentation in heavy-ion collisions. The particle flow algorithm has been adapted to the heavy-ion environment. The performance of jet reconstruction from particle flow objects in PbPb collisions using the anti-kT jet reconstruction algorithm is presented.