New constraints on extended scalar sectors from the trilinear Higgs coupling

The trilinear Higgs coupling λₕₕₕ is a crucial tool to probe the structure of the Higgs potential and to search for possible effects of physics beyond the Standard Model (SM). Focusing on the Two-Higgs-Doublet Model as a concrete example, we identify parameter regions in which λₕₕₕ is significantly enhanced with respect to its SM prediction. Taking into account all relevant corrections up to the two-loop level, we show that current experimental bounds on λₕₕₕ already rule out significant parts of the otherwise unconstrained parameter space. We illustrate the interpretation of the current results and future measurement prospects on λₕₕₕ for a benchmark scenario. Recent results from direct searches for BSM scalars in the A→ ZH channel and their implications will also be discussed in this context.