Gaugino mediated supersymmetry breaking

We consider supersymmetric theories where the standard-model quark and leptonfields are localized on a "3-brane" in extra dimensions, while the gauge andHiggs fields propagate in the bulk. If supersymmetry is broken on another3-brane, supersymmetry breaking is communicated to gauge and Higgs fields bydirect higher-dimension interactions, and to quark and lepton fields viastandard-model loops. We show that this gives rise to a realistic andpredictive model for supersymmetry breaking. The size of the extra dimensionsis required to be of order 10-100 times larger than fundamental scale (e.g. thestring scale). The spectrum is similar to (but distinguishable from) thepredictions of "no-scale" models. Flavor-changing neutral currents arenaturally suppressed. The \mu term can be generated by the Giudice-Masieromechanism. The supersymmetric CP problem is naturally solved if CP violationoccurs only on the observable sector 3-brane. These are the simplest models inthe literature that solve all supersymmetric naturalness problems.Comment: Refs. added. 12 pages, 1 figur