Search for leptonic charge asymmetry in tt¯ W production in final states with three leptons at √s = 13 TeV

Summary, in English

A search for the leptonic charge asymmetry (Acℓ) of top-quark-antiquark pair production in association with a W boson (tt¯ W) is presented. The search is performed using final states with exactly three charged light leptons (electrons or muons) and is based on s = 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider at CERN during the years 2015–2018, corresponding to an integrated luminosity of 139 fb −1. A profile-likelihood fit to the event yields in multiple regions corresponding to positive and negative differences between the pseudorapidities of the charged leptons from top-quark and top-antiquark decays is used to extract the charge asymmetry. At reconstruction level, the asymmetry is found to be −0.12 ± 0.14 (stat.) ± 0.05 (syst.). An unfolding procedure is applied to convert the result at reconstruction level into a charge-asymmetry value in a fiducial volume at particle level with the result of −0.11 ± 0.17 (stat.) ± 0.05 (syst.). The Standard Model expectations for these two observables are calculated using Monte Carlo simulations with next-to-leading-order plus parton shower precision in quantum chromodynamics and including next-to-leading-order electroweak corrections. They are −0.084−0.003+0.005 (scale) ± 0.006 (MC stat.) and −0.063−0.004+0.007 (scale) ± 0.004 (MC stat.) respectively, and in agreement with the measurements. [Figure not available: see fulltext.]. © 2023, The Author(s).

• Author: G. Aad; T.P.A. Åkesson; E.E. Corrigan; C. Doglioni; P.A. Ekman; J. Geisen; V. Hedberg; H. Herde; G. Jarlskog; B. Konya; E. Lytken; J.U. Mjörnmark; R. Poettgen; N.D. Simpson; E. Skorda; O. Smirnova; L. Zwalinski
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2023
• Language: English
• Publication/Series: Journal of High Energy Physics
• Volume: 2023
• Issue: 7
• Links: http://dx.doi.org/10.1007/JHEP07(2023)033
• Document type: Journal article
• Publisher: Springer
• Topic: Subatomic Physics
• Keywords: Hadron-Hadron Scattering; Top Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1029-8479