Quark-gluon Jet Discrimination At CMS

TL;DR

This paper presents a likelihood-based method to distinguish quark-initiated jets from gluon-initiated jets using CMS data at 8 TeV, aiding in more accurate physics analyses at the LHC.

Contribution

It introduces a new likelihood discriminant leveraging jet fragmentation observables to differentiate quark and gluon jets in CMS data.

Findings

Discriminant achieves effective quark-gluon separation.

Performance validated with Z+jets and dijet events.

Method enhances analysis precision in LHC experiments.

Abstract

Many physics analyses at the LHC are looking into processes where the signal jets are originating from quarks, while jets in the background are more gluon enriched. Based on observables sensitive to fundamental differences in the fragmentation properties of gluons and quarks, a likelihood discriminant is constructed to distinguish between jets originating from quarks and gluons. The performance of the tagger is evaluated using Z+jets and dijet events produced in proton-proton collisions at a centre-of-mass energy of 8 TeV, recorded by the CMS experiment at the LHC.