Erlangen 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 98: Higgs Physics X

T 98.1: Talk

Friday, March 20, 2026, 09:00–09:15, KH 02.013

Towards a CP-independent cross section measurement of ttH and tH production in the H→γγ decay channel at CMS — Johannes Erdmann, Jan Hermanns, •Florian Mausolf, and Peter Wissmann — III. Physikalisches Institut A, RWTH Aachen University

The top-quark Yukawa coupling, the Higgs boson’s strongest interaction with fermions, plays a central role in theory and experiment. While a purely CP-odd structure has been excluded experimentally, the possibility of a significant CP-odd admixture remains consistent with current LHC constraints. The presence of a CP-odd component or a change in the CP-even coupling strength would influence both the cross sections and kinematics of top-quark-associated Higgs-boson production processes. Particularly, the effect on the kinematics can lead to model dependencies of the measurement due to its effect on selection efficiencies.

This talk presents a measurement of ttH and tH production cross sections, with a special focus on minimizing model dependencies related to the CP-properties of the top-quark Yukawa coupling. This is achieved by using neural network classifiers trained with a decorrelation against such model assumptions in the training samples. The events are then categorized with a novel differentiable categorization optimization technique and the cross sections are extracted via a maximum likelihood fit using data recorded in 2022 and 2023 with the CMS detector.

Keywords: Higgs boson; Top quark; Yukawa coupling; CP violation