KEK Theory Seminar (Prof.Nobuhito Maru）
We address a question whether there exists a model of gauge-Higgs unification in 6-dimensional space-time, which successfully predicts the Weinberg angle and the mass ratios between Higgs boson and weak gauge bosons. First, we give a general argument on the condition to get a realistic prediction of the Weinberg angle, and find that triplet and sextet representations of the minimal SU(3) gauge group lead to the realistic prediction. We notice that in the models with one Higgs doublet, the predicted Higgs mass is always twice the W-boson mass at the leading order. However, in models with two Higgs doublets, Higgs mass can be smaller than twice the W-boson mass.