Parasupersymmetric Quantum Mechanics of Order 3 and a Generalized Witten   Index
  In this paper we generalize the Rubakov-Spiridonov parasupersymmetry algebra to the order 3 case. We also generalize the notion of the Witten index, and we provide a class of models satisfying our parasupersymmetry algebra. Finally, we show that there is a correspondence between the Hamiltonian and the index in our class of models. 
Marko Stosic and Roger Picken