Supernatural supersymmetry: Phenomenological implications of anomaly-mediated supersymmetry breaking

We discuss the phenomenology of supersymmetric models in which supersymmetry breaking terms are induced by the super-Weyl anomaly. Such a scenario is envisioned to arise when supersymmetry breaking takes place in another world, i.e., on another brane. We review the anomaly-mediated framework and study in detail the minimal anomaly-mediated model parametrized by only $3+1$ parameters: $M_{\mathrm{aux}},$ $m_0,$ $\tan \beta ,$ and $\mathrm{sgn}\left(\mu \right).\mathrm{}$ The renormalization group equations exhibit a novel “focus point” (as opposed to fixed point) behavior, which allows squark and slepton masses far above their usual naturalness bounds. We present the superparticle spectrum and highlight several implications for high energy colliders. Three lightest supersymmetric particle (LSP) candidates exist: the $W-\mathrm{ino},$ the stau, and the tau sneutrino. For the $W-\mathrm{ino}$ LSP scenario, light $W-\mathrm{ino}$ triplets with the smallest possible mass splittings are preferred; such $W-\mathrm{inos}$ are within reach of run II Fermilab Tevatron searches. Finally, we study a variety of sensitive low energy probes, including $\overrightarrow{b}s\gamma ,$ the anomalous magnetic moment of the muon, and the electric dipole moments of the electron and neutron.