Mo J, Tackmann FJ, Waalewijn WJ. A case study of quark-gluon discrimination at NNLL
' in comparison to parton showers.
THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2017;
77:770. [PMID:
31997931 PMCID:
PMC6956903 DOI:
10.1140/epjc/s10052-017-5365-9]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/03/2017] [Indexed: 06/08/2023]
Abstract
Predictions for our ability to distinguish quark and gluon jets vary by more than a factor of two between different parton showers. We study this problem using analytic resummed predictions for the thrust event shape up to NNLL' usinge + e - → Z → q q ¯ ande + e - → H → g g as proxies for quark and gluon jets. We account for hadronization effects through a nonperturbative shape function, and include an estimate of both perturbative and hadronization uncertainties. In contrast to previous studies, we find reasonable agreement between our results and predictions from both Pythia and Herwig parton showers. We find that this is due to a noticeable improvement in the description of gluon jets in the newest Herwig 7.1 compared to previous versions.
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