Scherk - Schwarz Supersymmetry Breaking with Radion Stabilization

We study the issue of radion stabilization within five-dimensional supersymmetric theories compactified on the orbifold S 1 /Z 2. We break supersymmetry by the Scherk-Schwarz mechanism and explain its implementation in the off-shell formulation of five dimensional supergravity in terms of the tensor and linear compensator multiplets. We show that radion stabilization may be achieved by radiative corrections in the presence of five-dimensional fields which are quasi-localized on the boundaries through the presence of Z 2 odd mass terms. For the mechanism to work the number of quasi-localized fields should be greater than 2 + N V − N h where N V and N h are the number of massless gauge-and hypermultiplets in the bulk. The radion is stabilized in a metastable Minkowski vacuum with a lifetime much larger than cosmological timescales. The radion mass is in the meV range making it interesting for present and future measurements of deviations from the gravitational inverse-square law in the submillimeter range.