Spin $3/2$ Interacting Fields and Heavy Baryon Chiral Perturbation   Theory
  We analyze the consistency of the Chiral Lagrangian approach to the description of the spin 3/2 interacting theory. We argue that to lowest order in the 1/m expansion, the formalism leads to the appropriated constraints and the theory is free of the so called ``off shell" ambiguities. 
M. Napsuciale and J. L. Lucio