New Standard for the Logarithmic Accuracy of Parton Showers

Melissa Van Beekveld, Mrinal Dasgupta, Basem Kamal El-Menoufi, Silvia Ferrario Ravasio, Keith Hamilton, Jack Helliwell, Alexander Karlberg, Pier Francesco Monni, Gavin P. Salam, Ludovic Scyboz, Alba Soto-Ontoso, Gregory Soyez

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We report on a major milestone in the construction of logarithmically accurate final-state parton showers, achieving next-to-next-to-leading-logarithmic (NNLL) accuracy for the wide class of observables known as event shapes. The key to this advance lies in the identification of the relation between critical NNLL analytic resummation ingredients and their parton-shower counterparts. Our analytic discussion is supplemented with numerical tests of the logarithmic accuracy of three shower variants for more than a dozen distinct event-shape observables in Z→qq¯ and Higgs→gg decays. The NNLL terms are phenomenologically sizeable, as illustrated in comparisons to data.

Original languageEnglish
Article number011901
Number of pages7
JournalPhysical Review Letters
Volume134
Issue number1
DOIs
Publication statusPublished - 10 Jan 2025

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