The top-quark Yukawa coupling is extracted from the distribution of the top-quark pair (tt¯) invariant mass in proton-proton collisions using 140 fb−1 of data at s=13 TeV collected in 2015–2018 by the ATLAS experiment at the Large Hadron Collider. In the region near the production threshold, the tt¯ 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 tt¯ 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 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 Yt< 2.1 relative to the Standard Model prediction is observed at 95% confidence level, consistent with the expected sensitivity.

Measurement of the top-quark Yukawa coupling from $$ t\overline{t} $$ production in the lepton+jets final state using pp collisions at $$ \sqrt{s}=13 $$ TeV with the ATLAS detector

Carrá, S.;Cresta, T.;Gaudio, G.;Introzzi, G.;Manco, G.;Negri, A.;Pareti, A.;Rebuzzi, D. M.;Romano, E.;
2026-01-01

Abstract

The top-quark Yukawa coupling is extracted from the distribution of the top-quark pair (tt¯) invariant mass in proton-proton collisions using 140 fb−1 of data at s=13 TeV collected in 2015–2018 by the ATLAS experiment at the Large Hadron Collider. In the region near the production threshold, the tt¯ 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 tt¯ 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 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 Yt< 2.1 relative to the Standard Model prediction is observed at 95% confidence level, consistent with the expected sensitivity.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11571/1557336
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