Hamiltonian anomalies of bound states in QED

The Bound State in QED is described in systematic way by means of nonlocal irreducible representations of the nonhomogeneous Poincare group and Dirac’s method of quantization. As an example of application of this method we calculate triangle diagram Para-Positronium → γγ. We show that the Hamiltonian approach to Bound State in QED leads to anomaly-type contribution to creation of pair of parapositronium by two photon.