Abstract
We study spontaneous supersymmetry breaking of five-dimensional supergravity theories from sixteen to eight supercharges in Minkowski vacua. This \( \mathcal{N}=4\to \mathcal{N}=2 \) breaking is induced by Abelian gaugings that require the introduction of self-dual tensor fields accompanying some of the vectors in the gravity and vector multiplets. These tensor fields have first-order kinetic terms and become massive by a Stückelberg-like mechanism. We identify the general class of \( \mathcal{N}=2 \) vacua and show how the \( \mathcal{N}=4 \) spectrum splits into massless and massive \( \mathcal{N}=2 \) multiplets. In particular, we find a massive gravitino multiplet, with two complex massive tensors, and a number of massive tensor multiplets and hypermultiplets. We determine the resulting \( \mathcal{N}=2 \) effective action for the massless multiplets obtained by integrating out massive fields. We show that the metric and Chern-Simons terms of the vectors are corrected at one-loop by massive tensors as well as spin-1/2 and spin-3/2 fermions. These contributions are independent of the supersymmetry-breaking scale and thus have to be included at arbitrarily low energies.