Speaker
Description
Extended Higgs sectors with scalar triplet fields are well motivated by scenarios for neutrino mass generation, and are characterized by the electroweak rho parameter deviating from unity already at tree level. Such models can lead to characteristic deviations in Higgs boson observables.
In this talk, we discuss precision predictions for decays of the 125 GeV Higgs boson in Higgs triplet models, focusing on both the complex and real triplet extensions of the Standard Model (SM). We calculate loop corrected decay rates of the 125 GeV Higgs boson in an on-shell renormalization scheme for models with $\rho \neq 1$ at tree level. We show that the decay rates can appear with characteristic deviations from the SM predictions as well as from other extended Higgs sectors such as two Higgs doublet models. In particular, the $h\to WW^*$ and $h\to ZZ^*$ decays can receive several-percent-level enhancements under current experimental and theoretical constraints. In addition, sizable new physics effects can appear in the $h\to\gamma\gamma$ decay and the Higgs self-coupling. We discuss the characteristic correlation patterns of these deviations in both complex and real triplet models and indirect tests at the High-Luminosity LHC and future Higgs factories.
This talk is based on the paper arXiv:2601.15983 [hep-ph] (JHEP 05 (2026) 136, DOI: 10.1007/JHEP05(2026)136).