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Radiative brane-mass terms in D>5 orbifold gauge theories

A gauge theory with gauge group G defined in D>4 space-time dimensions can be broken to a subgroup H on four dimensional fixed point branes, when compactified on an orbifold. Mass terms for extra dimensional components of gauge fields A_i (brane scalars) might acquire (when allowed by the brane symmetries) quadratically divergent radiative masses and thus jeopardize the stability of the four-dimensional theory. We have analyzed Z_2 compactifications and identified the brane symmetries remnants of the higher dimensional gauge invariance. No mass term is allowed for D=5 while for D>5 a tadpole ε^{ij}F_{ij}^αcan appear when there are U_α(1) factors in H. A detailed calculation is done for the D=6 case and it is established that the tadpole is related, although does not coincide, with the U_α(1) anomaly induced on the brane by the bulk fermions. In particular, no tadpole is generated from gauge bosons or fermions in real representations