What is the scale of supersymmetry breaking?

Abstract

For a long time, it has been widely assumed that if the underlying laws of nature are supersymmetric, supersymmetry is broken at a scale intermediate between the weak scale and the Planck mass. The construction of realistic models of dynamical supersymmetry breaking in which supersymmetry is broken at a much lower scale, as well as a growing appreciation of the supersymmetric flavor problem has reopened this question. After reviewing some ideas for understanding the microscopic origin of the soft breaking parameters in the context of string theory, I turn to low energy breaking. Independent of the details of the underlying theory, events with photons and missing energy, like the CDF $e^+e^-\gamma \gamma \not{E}_T$ event, are likely signals of low energy breaking. I briefly review the predictions of the simplest model of low energy supersymmetry breaking for the soft breaking parameters (MGM), and then ask what sorts of generalizations are possible. It turns out that if all couplings are weak, there are only a limited number of ways to modify the model.