Effective interactions of a light gravitino

Abstract

We review some recent results on the effective interactions of a light gravitino with ordinary particles. In particular, we discuss on a simple example a novel aspect of the low-energy theorems for broken supersymmetry: in the effective lagrangian describing the goldstino couplings to matter, there are terms bilinear in the goldstino that, already at the lowest non-trivial order, are not entirely controlled by the supersymmetry-breaking scale, and introduce additional free parameters. We conclude by mentioning some phenomenological implications, including a lower bound on the gravitino mass from collider data.