Generalizations of the Sugawara Model

Two generalizations of Sugawara models are discussed. In the first, new interactions are introduced by altering the current commutators but retaining the "free" form of $T_{\mu \nu }$, as exemplified by a simple effective ${\pi }^0-2\gamma$ interaction, which is compared with the standard triangle-diagram results. The second permits non-quadratic $T_{\mu \nu }$, which retain the "algebra" part of the current commutators; these models avoid the Dashen-Frishman parity degeneracy.