Dynamical symmetry breaking in 5D Gauge-Higgs unification models on orbifold

摘要

Recently, there are much progress in the higher dimensional gauge theories. One of the most fascinating motivations of considering the higher dimensional gauge theory is that gauge and Higgs fields can be unified {see, for examples, [3, 4]). The higher dimensional components of gauge fields appear as scalar fields below the compactification scale, and these scalar fields are identified as the "Higgs fields" in the gauge-Higgs unified unification. The "Higgs fields" have only finite masses of order the compactification scale, since the masses of "Higgs fields" are forbidden by the higher dimensional gauge invariance. The "adjoint Higgs fields" appear through the Sl compactification in 5D theory, while the "Higgs doublet fields" appear through the orbifold compactifications. In order to obtain the "Higgs doublets" from the gauge fields in higher dimensions, the gauge group must be lager than the standard model (SM) gauge group, and the gauge symmetries are reduced by the orbifold boundary conditions of extra dimensions. In 5D M = 1 supersymmetric (SUSY) gauge theory, the identification of "Higgs fields" as a part of the gauge supermultiplet has been considered on Sl/Z2 orbifold, for examples, Refs.[5, 6, 7, 8].