A note on Gaugino masses in Kaluza-Klein/radion mediated SUSY breaking

Abstract

We review the equivalence of two approaches to study theories with gauge fields in extra spatial dimensions, namely the "4D" approach (with KK states) and the "5D" approach (with matching to the 4D theory at the compactification scale). In particular, we reiterate that there are two different power-law scalings of "effective" gauge couplings. In a supersymmetric framework with SUSY breaking in the radius modulus, i.e. the field which fixes the size of the extra dimensions, these two approaches seem to give gaugino masses at loop-level (with a possible enhancement due to large number of Kaluza-Klein states) [1], and tree-level [2], respectively. We show explicitly how this discrepancy can be resolved.