Evidence for the charge asymmetry in pp → tt¯ production at √s = 13 TeV with the ATLAS detector



Aad, G, Abbott, B, Abbott, DC, Abeling, K, Abidi, SH, Aboulhorma, A, Abramowicz, H, Abreu, H, Abulaiti, Y, Abusleme Hoffman, AC
et al (show 2925 more authors) (2023) Evidence for the charge asymmetry in pp → tt¯ production at √s = 13 TeV with the ATLAS detector. Journal of High Energy Physics, 2023 (8). 77-.

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Abstract

<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>Inclusive and differential measurements of the top–antitop (<jats:inline-formula><jats:alternatives><jats:tex-math>$$ t\overline{t} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math></jats:alternatives></jats:inline-formula>) charge asymmetry <jats:inline-formula><jats:alternatives><jats:tex-math>$$ {A}_{\textrm{C}}^{t\overline{t}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>A</mml:mi> <mml:mi>C</mml:mi> <mml:mrow> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> and the leptonic asymmetry <jats:inline-formula><jats:alternatives><jats:tex-math>$$ {A}_{\textrm{C}}^{\ell \overline{\ell}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>A</mml:mi> <mml:mi>C</mml:mi> <mml:mrow> <mml:mi>ℓ</mml:mi> <mml:mover> <mml:mi>ℓ</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> are presented in proton–proton collisions at <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \sqrt{s} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math></jats:alternatives></jats:inline-formula> = 13 TeV recorded by the ATLAS experiment at the CERN Large Hadron Collider. The measurement uses the complete Run 2 dataset, corresponding to an integrated luminosity of 139 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup>, combines data in the single-lepton and dilepton channels, and employs reconstruction techniques adapted to both the resolved and boosted topologies. A Bayesian unfolding procedure is performed to correct for detector resolution and acceptance effects. The combined inclusive <jats:inline-formula><jats:alternatives><jats:tex-math>$$ t\overline{t} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math></jats:alternatives></jats:inline-formula> charge asymmetry is measured to be <jats:inline-formula><jats:alternatives><jats:tex-math>$$ {A}_{\textrm{C}}^{t\overline{t}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>A</mml:mi> <mml:mi>C</mml:mi> <mml:mrow> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> = 0<jats:italic>.</jats:italic>0068 ± 0<jats:italic>.</jats:italic>0015, which differs from zero by 4.7 standard deviations. Differential measurements are performed as a function of the invariant mass, transverse momentum and longitudinal boost of the <jats:inline-formula><jats:alternatives><jats:tex-math>$$ t\overline{t} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math></jats:alternatives></jats:inline-formula> system. Both the inclusive and differential measurements are found to be compatible with the Standard Model predictions, at next-to-next-to-leading order in quantum chromodynamics perturbation theory with next-to-leading-order electroweak corrections. The measurements are interpreted in the framework of the Standard Model effective field theory, placing competitive bounds on several Wilson coefficients.</jats:p>

Item Type: Article
Uncontrolled Keywords: Bioengineering
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 21 Sep 2023 14:44
Last Modified: 18 Mar 2024 03:46
DOI: 10.1007/jhep08(2023)077
Open Access URL: https://link.springer.com/article/10.1007/JHEP08(2...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3172927