Higgs potential in gauge-Higgs unification with a flat extra dimension

We analyze the structure of Higgs potential in gauge-Higgs unification with a flat extra dimension. As concrete model, we first consider cases where Standard Model doublet is embedded into higher-dimensional SU(3)w gauge multiplet five-dimensional Lorentz symmetry relaxed. In this model violation, deviation resulting triple boson coupling from its SM prediction shown to be less than 10% when compactification scale larger experimental lower bound, which around 5 TeV. Next, examine other similar models It pointed out that even such shape vacuum quickly approaches minimal one as dimension increases. An observable at planned lepton colliders will necessitate significant extensions models.