New Constraints on Extended Higgs Sectors from the Trilinear Higgs Coupling
Henning Bahl, Johannes Braathen, G. Weiglein
Abstract
The trilinear Higgs coupling λ_{hhh} is crucial for determining the structure of the Higgs potential and for probing possible effects of physics beyond the standard model. Focusing on the two-Higgs-doublet model as a concrete example, we identify parameter regions in which λ_{hhh} is significantly enhanced with respect to the standard model. Taking into account all relevant corrections up to the two-loop level, we show that already current experimental bounds on λ_{hhh} rule out significant parts of the parameter space that would otherwise be unconstrained. We illustrate the interpretation of the results on λ_{hhh} for a benchmark scenario. Similar results are expected for wide classes of models with extended Higgs sectors.