Triplet Higgs bosons at e⁺e^- colliders

Abstract

We investigate the possibility of probing the triplet Higgs boson sector via single charged Higgs production in the process e⁺e^-→ H⁺lν_l, at high energy electron-positron colliders, using the tree level H⁺W^-Z coupling which is a unique feature of such models. We find that even LEP-200 can give nontrivial information upto M_H±≃120 GeV if the doublet -triplet mixing is not restricted by the current value of the ρ parameter which is the case in models with a custodial symmetry. Further we point out that in such models, the 4-body, tree level decay H⁺ → W^∗Z^∗→4 fermions dominates and hence provides a very clean signal when the four fermions are leptons. At NLC the discovery range for the charged Higgs in triplet models via this process is ~ 400 GeV.