Divergences and Symmetries in Higgs-Gauge Unification Theories

In theories with extra dimensions the Standard Model Higgs field can be identified with the internal components of higher-dimensional gauge fields (Higgs-gauge unification). The higher-dimensional gauge symmetry prevents the Higgs mass from quadratic divergences, but at the fixed points of the orbifold this symmetry is broken and divergences can arise if U(1) subgroups are conserved. We show that another symmetry, remnant of the internal rotation group after orbifold projection, can avoid the generation of such divergences.