Confining the Higgs sector via the investigation of di-tau final states with LHC Run II data

Common extensions to the Standard Model Higgs sector, such as two-Higgs-doublet models as for example the Minimal Supersymmetric Standard Model, predict the presence of additional Higgs bosons. In these extensions the coupling of the additional Higgs bosons to down-type fermions, such as τ-leptons, is enlarged for large parameter spaces. As a result, the decay of these Higgs bosons into a pair of τ-leptons is one of the most promising channels to search for new physics. In this thesis, this decay channel is explored using data recorded by the CMS experiment in the year 2016 at a center-of-mass energy of √s=13TeV. The analysis methods, selection criteria and the resulting uncertainty model are detailed. No evidence for additional Higgs bosons is found and exclusion limits on the cross section times branching ratio for further Higgs bosons are set. These exclusion limits constrain the phase space for possible deviations from the Standard Model Higgs sector. Examples of scenario-specific exclusion limits are given and possibilities for interpretations in the context of further scenarios based on the results of this analysis are discussed.