Abstract

The standard model (SM) Higgs sector predicts exactly one physical Higgs boson with CP-even couplings to the SM particles. The observation of a spin-0 boson by the ATLAS and CMS experiments with mass around 125 GeV appears to fulfil this prediction, however, many extended Higgs sectors can also accommodate such a particle. These models usually predict modified couplings and/or properties of the 125 GeV boson, which can be directly tested by precision Higgs measurements at the LHC. In several such models the Higgs interactions with SM particles can also violate CP conservation. Observing such interactions would conflict with the SM predictions, and may provide insight into the observed excess of matter over antimatter in the universe. This seminar will discuss the latest Higgs to tautau results from the CMS experiment using 137/fb of 13 TeV data collected between 2016-2018. This will include cross section measurements for the dominant Higgs production modes and differential measurements in the Simplified Template Cross Section (STXS) scheme. The first direct measurement of the CP properties of the Higgs to tau tau coupling will also be presented