Precision observables in SU(2) x U(1) models with an additional Higgs triplet

Original · EN

Electroweak precision observables are calculated at complete 1-loop order in the extension of the standard model by an extra Higgs triplet, where the ρ-parameter can be different from unity already at the tree level. One additional data point is required for fixing the input parameters. In the on-shell renormalization scheme the leptonic mixing angle ²θₑ at the Z peak is chosen, together with the conventional input α, MZ, Gμ, mₜ. The calculated observables depend on the mass of the doublet Higgs boson H⁰ and on the masses of the extra non-standard Higgs bosons as free parameters. The predictions of the standard model and the triplet model coincide for all observables in the experimental range of the top mass mₜ=175± 6 GeV. In the triplet model, all observables which show a dependence on the doublet Higgs mass Mₕ₀ are consistent with a low value of Mₕ₀.