A measurement of single top-quark production in the s-channel is performed in proton–proton collisions at a centre-of-mass energy of 13 TeV with the ATLAS detector at the CERN Large Hadron Collider. The dataset corresponds to an integrated luminosity of 139 fb−1 . The analysis is performed on events with an electron or muon, missing transverse momentum and exactly two b-tagged jets in the final state. A discriminant based on matrix element calculations is used to separate single-top-quark s-channel events from the main background contributions, which are top-quark pair production and W-boson production in association with jets. The observed (expected) signal significance over the background-only hypothesis is 3.3 (3.9) standard deviations, and the measured cross-section is σ = 8.2 +3.5 −2.9 pb, consistent with the Standard Model prediction of σ SM = 10.32+0.40 −0.36 pb.

G. Aad, B. Abbott, D. C. Abbott, K. Abeling, S. H. Abidi, A. Aboulhorma, et al. (2023). Measurement of single top-quark production in the s-channel in proton–proton collisions at √s = 13 TeV with the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS, 2023(6), 0-46 [10.1007/jhep06(2023)191].

Measurement of single top-quark production in the s-channel in proton–proton collisions at √s = 13 TeV with the ATLAS detector

G. L. Alberghi;F. Alfonsi;M. Bindi;D. Boscherini;G. Cabras;G. Carratta;N. Cavalli;L. Clissa;S. De Castro;F. Fabbri;L. Fabbri;M. Franchini;A. Gabrielli;F. Lasagni Manghi;L. Massa;