Properties of <i>g</i> → <i>b</i>(<i>b</i>)over-bar at small opening angles in <i>pp</i> collisions with the ATLAS detector at √<i>s</i>=13 TeV

Aaboud, M, Aad, G, Abbott, B, Abbott, DC, Abdinov, O, Abeloos, B, Abhayasinghe, DK, Abidi, SH, AbouZeid, OS, Abraham, NL
et al (show 2888 more authors) (2019) Properties of <i>g</i> → <i>b</i>(<i>b</i>)over-bar at small opening angles in <i>pp</i> collisions with the ATLAS detector at √<i>s</i>=13 TeV. PHYSICAL REVIEW D, 99 (5). 052004-.

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The fragmentation of high-energy gluons at small opening angles is largely unconstrained by present measurements. Gluon splitting to $b$-quark pairs is a unique probe into the properties of gluon fragmentation because identified $b$-tagged jets provide a proxy for the quark daughters of the initial gluon. In this study, key differential distributions related to the $g\rightarrow b\bar{b}$ process are measured using 33 fb$^{-1}$ of $\sqrt{s}=13$ TeV $pp$ collision data recorded by the ATLAS experiment at the LHC in 2016. Jets constructed from charged-particle tracks, clustered with the anti-$k_t$ jet algorithm with radius parameter $R = 0.2$, are used to probe angular scales below the $R=0.4$ jet radius. The observables are unfolded to particle level in order to facilitate direct comparisons with predictions from present and future simulations. Multiple significant differences are observed between the data and parton shower Monte Carlo predictions, providing input to improve these predictions of the main source of background events in analyses involving boosted Higgs bosons decaying into $b$-quarks.

Item Type: Article
Additional Information: 39 pages in total, author list starting page 23, 6 figures, 1 table, submitted to PRD. All figures including auxiliary figures are available at
Uncontrolled Keywords: hep-ex, hep-ex
Depositing User: Symplectic Admin
Date Deposited: 08 Apr 2019 09:11
Last Modified: 11 Oct 2023 07:33
DOI: 10.1103/PhysRevD.99.052004
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