Differential tt̅ cross-section measurements using boosted top quarks in the all-hadronic final state with 139 fb⁻¹ of ATLAS data

Anders, J.K.; Beck, H.P.; Chatterjee, M.; Ereditato, A.; Franconi, L.; Halser, L.; Haug, S.; Ilg, A.; Lehmann, N.; Müller, R.; O'Neill, A.P.; Weber, M.S. (2023). Differential tt̅ cross-section measurements using boosted top quarks in the all-hadronic final state with 139 fb⁻¹ of ATLAS data. Journal of High Energy Physics, 04 Springer 10.1007/JHEP04(2023)080

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Measurements of single-, double-, and triple-differential cross-sections are pre-
sented for boosted top-quark pair-production in 13 TeV proton–proton collisions recorded
by the ATLAS detector at the LHC. The top quarks are observed through their hadronic
decay and reconstructed as large-radius jets with the leading jet having transverse momentum (pT) greater than 500 GeV. The observed data are unfolded to remove detector effects. The particle-level cross-section, multiplied by the t¯t → W W b¯b branching fraction and measured in a fiducial phase space defined by requiring the leading and second-leading jets to have pT > 500 GeV and pT > 350 GeV, respectively, is 331 ± 3(stat.) ± 39(syst.) fb. This is approximately 20% lower than the prediction of 398+48−49 fb by Powheg+Pythia 8 with next-to-leading-order (NLO) accuracy but consistent within the theoretical uncertainties. Results are also presented at the parton level, where the effects of top-quark decay, parton showering, and hadronization are removed such that they can be compared with fixed-order next-to-next-to-leading-order (NNLO) calculations. The parton-level cross-section, measured in a fiducial phase space similar to that at particle level, is 1.94 ± 0.02(stat.) ± 0.25(syst.) pb. This agrees with the NNLO prediction of 1.96+0.02−0.17 pb. Reasonable agreement with the differential cross-sections is found for most NLO models, while the NNLO calculations are generally in better agreement with the data. The differential cross-sections are interpreted using a Standard Model effective field-theory formalism and limits are set on Wilson coefficients of several four-fermion operators.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP)
10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)

UniBE Contributor:

Anders, John Kenneth, Beck, Hans Peter, Chatterjee, Meghranjana, Ereditato, Antonio, Franconi, Laura, Halser, Lea, Haug, Sigve, Ilg, Armin, Lehmann, Niklaus, Müller, Roman, O'Neill, Aaron Paul, Weber, Michele

Subjects:

500 Science > 530 Physics

ISSN:

1029-8479

Publisher:

Springer

Language:

English

Submitter:

BORIS Import LHEP

Date Deposited:

15 Feb 2024 11:56

Last Modified:

15 Feb 2024 12:05

Publisher DOI:

10.1007/JHEP04(2023)080

Additional Information:

Kollaboration - Es sind nur die Berner Autor*innen namentlich erwaehnt; the ATLAS collaboration

Uncontrolled Keywords:

Hadron-Hadron Scattering , Jet Substructure and Boosted Jets, Top Physics

BORIS DOI:

10.48350/191928

URI:

https://boris.unibe.ch/id/eprint/191928

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