The non-linear realisation structure of models with spontaneously broken supersymmetry

Abstract

It is proved that any superfield action with spontaneously broken supersymmetry can be equivalently rewritten in terms of the Volkov-Akulov non-linear realisation quantities. Such a rearrangement is advantageous in that it makes the underlying group structure of spontaneous supersymmetry breaking explicit. Simple algorithms for passing to the nonlinear parametrisation are given, and the general form of a reparameterised action is presented. The authors also analyse the problem of representing the Volkov-Akulov action by constrained superfield actions and find that proper constraints may sometimes be achieved through setting mass parameters in the Lagrangian to infinity, just as in standard linear sigma models. For illustration, they study the nonlinear realisation structure and the infinite-mass limit of the Fayet-Iliopoulos model. The limiting form of the relevant action is found to be different for different regimes of spontaneous breaking. Only in the case when supersymmetry is broken together with internal O(2) symmetry is the limiting action the Volkov-Akulov one.