Building a Nest at Tree Level: Classical Metastability and Non-Trivial   Vacuum Structure in Supersymmetric Field Theories
  It is becoming increasingly clear that metastable vacua may play a prominent role in supersymmetry-breaking. To date, however, this idea has been realized only in models where non-perturbative dynamics complicates the analysis of metastability. In this paper, we present a simple construction in which metastable vacua occur classically, i.e., at tree-level, and in which supersymmetry-breaking is sourced by both D-terms and F-terms. All relevant dynamics is perturbative, and hence calculations of vacuum energies and lifetimes can be performed explicitly. Moreover, we find that our construction can even give rise to multiple non-supersymmetric vacua which are degenerate. The non-trivial vacuum structure of such models therefore suggests that they can provide a rich arena for future studies of vacuum metastability in supersymmetric field theories. Our results may also have important consequences for Z' phenomenology and the string landscape. 
Keith R. Dienes, Brooks Thomas