THEORY OF CURRENTS WITHOUT TOO MUCH SYMMETRY

It is shown that it is possible to have a theory of currents without parity doubling if the algebra-of-fields commutation relations are changed by the introduction of operator Schwinger terms. In addition, it is necessary to impose a relationship among the currents generating the theory. The nonlinear formulation of the σ model involving only the pion field is shown to be an example with these properties. © 1969 The American Physical Society.