Standard(-like) Model from an SO(12) Grand Unified Theory in six-dimensions with S2 extra-space

We analyze a gauge-Higgs unification model which is based on a gauge theory defined on a six-dimensional spacetime with an S2 extra-space. We impose a symmetry condition for a gauge field and non-trivial boundary conditions of the S2. We provide the scheme for constructing a four-dimensional theory from the six-dimensional gauge theory under these conditions. We then construct a concrete model based on an SO(12) gauge theory with fermions which lie in a 32 representation of SO(12), under the scheme. This model leads to a Standard Model(-like) gauge theory which has gauge symmetry SU(3)×SU(2)L×U(1)Y(×U(1)2) and one generation of SM fermions, in four-dimensions. The Higgs sector of the model is also analyzed, and it is shown that the electroweak symmetry breaking and the prediction of W-boson and Higgs-boson masses are obtained.