Measurement of the top-quark Yukawa coupling from $$ t\overline{t} $$ production in the lepton+jets final state using $\textit{pp}$ collisions at $$ \sqrt{s}=13 $$ TeV with the ATLAS detector
G. Aad (CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille, France)
; E. Aakvaag (Department for Physics and Technology, University of Bergen, Bergen, Norway); B. Abbott (Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK, U.S.A.); S. Abdelhameed (New York University Abu Dhabi, Abu Dhabi, United Arab Emirates); K. Abeling (II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany); et al - Show all 2928 authors
The top-quark Yukawa coupling is extracted from the distribution of the top-quark pair ( $$ t\overline{t} $$ ) invariant mass in proton-proton collisions using 140 fb of data at $$ \sqrt{s}=13 $$ TeV collected in 2015–2018 by the ATLAS experiment at the Large Hadron Collider. In the region near the production threshold, the $$ t\overline{t} $$ invariant mass spectrum is sensitive to electroweak virtual corrections, including contributions from Higgs boson exchange, thereby providing sensitivity to the top-quark Yukawa coupling. This is the first measurement in ATLAS that aims to obtain this coupling exploiting this approach. The $$ t\overline{t} $$ system is reconstructed in the single-lepton final state, requiring exactly one isolated electron or muon and at least four jets with at least two identified as originating from $\textit{b}$-quarks. The measured Yukawa coupling is found to be in good agreement with the Standard Model prediction. An upper limit on the top-quark Yukawa coupling strength of $\textit{Y}$ $\textit{
