One-loop Higgs mass finiteness in supersymmetric Kaluza–Klein theories

We analyze the one-loop ultraviolet sensitivity of the Higgs mass in a five-dimensional supersymmetric theory compactified on the orbifold S1/Z2, with superpotential localized on a fixed-point brane. Four-dimensional supersymmetry is broken by Scherk–Schwarz boundary conditions. Kaluza–Klein interactions are regularized by means of a brane Gaussian distribution along the extra dimension with length ls≃Λ−1s, where Λs is the cutoff of the five-dimensional theory. The coupling of the n-mode, with mass M(n), acquires the n-dependent factor exp{−(M(n)/Λs)2/2}, which makes it to decouple for M(n)⪢Λs. The sensitivity of the Higgs mass on Λs is strongly suppressed and quadratic divergences cancel by supersymmetry. The one-loop correction to the Higgs mass is finite and equals, for large values of Λs, the value obtained by the so-called KK-regularization.