1 A proposal for a first class conversion formalism based on the symmetries of the Wess - Zumino terms

We propose a new procedure to embed second class systems by introducing Wess-Zumino (WZ) fields in order to unveil hidden symmetries existent in the models. This formalism is based on the direct imposition that the new Hamiltonian must be invariant by gauge-symmetry transformations. An interesting feature in this approach is the possibility to fix the WZ fields in a convenient way, which leads to preserve the gauge symmetry in the original phase space. Consequently, the gauge invariant Hamiltonian can be written only in terms of the original phase-space variables. We apply this formalism to important physical models: the reduced-SU(2) Skyrme model, the Chern-Simons-Proca quantum mechanics and the chiral bosons field theory. In all these examples, the gauge-invariant Hamiltonians are derived in a very simple way when compared with the traditional BFFT approach [1].