Ulrich Husemann - The Quest for ttH Production

How does the Higgs boson couple to fermions? This is one of the key questions at the CERN Large Hadron Collider (LHC), where determining the properties of the Higgs boson has become a central research goal in recent years. As the standard model of particle physics predicts couplings proportional to the fermion mass, studying the heaviest known elementary fermion, the top quark, is a natural choice. The associated production of a Higgs boson and a top quark-antiquark pair (ttH production) is a direct probe of the tree-level coupling of the Higgs boson to up-type fermions. However, establishing this process experimentally turns out to be a formidable data-analysis challenge. In this presentation, the quest for ttH production at the LHC will be illustrated, which culminated in the observation of the process in 2018.