Résumé |
Extensions of the Standard Model often come with additional, possibly electroweakly charged Higgs states,
the prototypal example being the Two-Higgs-Doublet Model. While collider phenomenology does not
exclude the possibility for some of these new scalar fields to be light, it is relatively natural to consider
masses in the multi-TeV range, where decoupling of the SM-like boson is almost guaranteed. The
appearance of a hierarchy between the new-physics states and the electroweak scale then leads to sizable
electroweak corrections in e.g. the decays of the heavy Higgs, which are dominated by effects of infrared
type, namely Sudakov logarithms. Such radiative contributions obviously affect the two-body decays, but
should also be paired with the radiation of electroweak (or lighter Higgs) bosons for a consistent picture at
the one-loop order. Resummation of the leading terms is also relatively easy to achieve. We re-visit these
questions in the specific case of the fermionic decays of heavy Higgs particles in the Next-to-Minimal
Supersymmetric Standard Model, in particular pointing out the consequences of the three-body final states
for the branching ratios of the heavy scalars. |