Abstract
We construct the action of a relativistic spinning particle from a non-linear realization of a space-time odd vector extension of the Poincaré group. For particular values of the parameters appearing in the lagrangian the model has a gauge world-line supersymmetry. As a consequence of this local symmetry there are BPS solutions in the model preserving 1/5 of the supersymmetries. A supersymmetric invariant quantization produces two decoupled 4d Dirac equations.