  The simplest Gauge-Higgs Unification model is a five-dimensional SU(2) gauge
theory compactified on the S^1/Z_2 orbifold, such that on the four-dimensional
boundaries of space-time there is an unbroken U(1) symmetry and a complex
scalar, the latter identified with the Higgs boson. Perturbatively the U(1)
remains spontaneously unbroken. Earlier lattice Monte Carlo simulations
revealed however that the spontaneous breaking of the U(1) does occur at the
non-perturbative level. Here, we verify the Monte Carlo result via an
analytical lattice Mean-Field expansion.
