Fayet–Iliopoulos Terms in 5D Orbifold Supergravity

Abstract

We discuss a locally supersymmetric formulation for the boundary Fayet-Iliopoulos (FI) terms in 5-dimensional U(1) gauge theory on S1/Z2, using the four-form multiplier mechanism to introduce the necessary Z2-odd FI coefficient. Some physical consequences of the boundary FI terms, e.g., supersymmetry/gauge symmetry breakings and the generation of 5D kink mass for hypermultiplet, are studied within the full supergravity framework. For models giving a flat spacetime geometry, the only meaningful deformation of vacuum configuration induced by the FI terms is a kink-type vacuum expectation value of the vector multiplet scalar field. On the other hand, for models giving an warped geometry, the boundary FI terms can lead to more interesting vacuum deformation breaking gauge symmetry and/or N = 1 supersymmetry, and also provide a non-trivial connection between the orbifold radius and the hyperscalar dynamics on the boundaries which may be useful for the radion stabilization.