Search for CP violation in fermionic couplings of the Higgs boson generated by gluon-gluon fusion with the CMS Detector

The discovery of the Higgs boson in 2012 has been one of the greatest successes of the standard model (SM) of elementary particles. A major scientific effort has been performed to measure all the particles’ properties. So far no deviation from the SM prediction has been found. The precise determination of the properties of the Higgs boson under parity and charge-conjugation transformations, namely the CP properties, is, however, still a major challenge in Higgs physics. Being predicted as a scalar particle, observations up to now only exclude the pure pseudoscalar scenario. A small pseudoscalar admixture to the prediction of the SM is still a valid scenario. The detection of such an admixture would prove CP violation in the Higgs sector, contributing potentially to the matter-antimatter asymmetry in the universe. This thesis presents a framework for an analysis that is dedicated to the precise measurement of the CP properties of the Higgs boson in the gluon-gluon fusion process. It evaluates the performance of a measurement of CP properties utilizing an effective field theory (EFT). With the presented setup and statistical tools the result is quoted in terms of an expected sensitivity for the measurement of the CP mixing angle of the Higgs boson to top quarks. The presented analysis is capable of measuring the CP mixing angle with an accuracy of 41°.