Measurement of the top-Yukawa coupling in top quark associated Higgs boson production and blueprint for a novel top quark decay width measurement in Wb scattering

The production of top quarks in association with a Higgs boson allows to directly measure the Yukawa coupling between the top quark and the Higgs boson. While the production of a Higgs boson with a top quark pair (ttH) is only sensitive to absolute values of this coupling, the production with a single top quark (tH) is through interference also sensitive to the relative sign between the top-Yukawa coupling and the Higgs-Vector boson coupling. In addition to the search for tH production, the top-Yukawa coupling is measured in two different coupling scenarios: A Standard Model scenario and a scenario introducing coupling to an additional pseudoscalar Higgs boson.

In addition, a new method to measure the top quark decay width in Wb scattering is developed and the performance of flavor tagging at trigger level in 2023 is evaluated.