SIGMA-MODELS WITH (2, 2) WORLD-SHEET SUPERSYMMETRY

We propose a new mechanism for constructing (2,2) superspace actions for WZWN sigma models. We use the already known semi-chiral superfields, but we choose the Lagrangian in a special way, so that it has a gauge invariance capable of eliminating half of the initially propagating degrees of freedom. Thus we avoid the doubling of the target space dimension. The nonlinear differential conditions on the Lagrangian are derived and it is shown that this type of action corresponds to the general (2,2) sigma model.