Systematics of quark/gluon tagging

Philippe Gras, Stefan Höche, Deepak Kar, Andrew Larkoski, Leif Lönnblad, Simon Plätzer, Andrzej Siódmok, Peter Skands, Gregory Soyez, Jesse Thaler

Research output: Contribution to journalArticleResearchpeer-review

54 Citations (Scopus)

Abstract

By measuring the substructure of a jet, one can assign it a “quark” or “gluon” tag. In the eikonal (double-logarithmic) limit, quark/gluon discrimination is determined solely by the color factor of the initiating parton (CF versus CA). In this paper, we confront the challenges faced when going beyond this leading-order understanding, using both parton-shower generators and first-principles calculations to assess the impact of higher-order perturbative and nonperturbative physics. Working in the idealized context of electron-positron collisions, where one can define a proxy for quark and gluon jets based on the Lorentz structure of the production vertex, we find a fascinating interplay between perturbative shower effects and nonperturbative hadronization effects. Turning to proton-proton collisions, we highlight a core set of measurements that would constrain current uncertainties in quark/gluon tagging and improve the overall modeling of jets at the Large Hadron Collider.

Original languageEnglish
Article number91
Number of pages50
JournalJournal of High Energy Physics
Volume2017
Issue number7
DOIs
Publication statusPublished - 1 Jul 2017

Keywords

  • Jets
  • QCD Phenomenology

Cite this