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arXiv · 2302.01283

Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector

ATLAS Collaboration
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Abstract

This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139 fb$^{-1}$ of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688 $\pm$ 23 (stat.) $^{+75}_{-71}$ (syst.) fb, to be compared with the standard model prediction of 515 $^{+36}_{-42}$ fb at next-to-leading order in QCD.

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ATLAS Collaboration. 2023-02-02. Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector. https://doi.org/10.1103/physrevlett.131.181901

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