MASSIVE (P,Q)-SUPERSYMMETRIC SIGMA-MODELS REVISITED

We recently obtained the conditions on the couplings of the general two-dimensional massive sigma model required by (p, q)-supersymmetry. Here we compute the Poisson bracket algebra of the supersymmetry and central Noether charges, and show that the action is invariant under the automorphism group of this algebra. Surprisingly, for the (4, 4) case the automorphism group is always a subgroup of SO (3), rather than SO (4). We also re-analyse the conditions for (2, 2) and (4, 4) supersymmetry of the zero torsion model without assumptions about the central change matrix.