Coupling constant dependence of the Kaluza-Klein spectrum in five-dimensional SQCD on S1

We investigate the Kaluza-Klein (KK) spectrum of N=1 supersymmetric gauge theory compactified on a circle. We concentrate on a model with the gauge group SU(2) and four massless matter fields in the fundamental representation. We derive the exact mass formula of KK modes using Seiberg-Witten theory. From the mass formula and the D3-brane probe realization, we determine the spectrum of the KK modes of the matter fields and gauge fields. We find that the lightest KK state of the gauge fields is stable in the entire vacuum moduli space, while the lightest KK state of the matter fields decays more readily than other KK states in one region of the moduli space. This region becomes small as we decrease the five-dimensional gauge coupling constant g5, and vanishes in the limit g5→0. This result continuously connects the known KK spectrum in the weak coupling limit and that in the strong coupling limit. (author)