Heavy quarkonia in a bilocal effective theory

The effective model of the unified description of quarkonia by the covariant generalization of the instantaneous interaction is considered. It is shown that low energy theorems of the chiral algebra (spontaneously symmetry breaking, Goldstone theorem), a nonrelativistic limit for heavy quarkonia and a heavy quark symmetry in the framework of the model are reproduced. The solutions of the Schwinger-Dyson and Bethe-Salpeter equations for light and heavy quarkonia and their excitations are obtained. (author)