Duality diagrams and the decays of the psi and psi'

Duality diagrams are applied to the psi and psi' decays. It is proposed that the psi→3π decay is described by a Virasoro formula, and it is shown that the low mass ππ suppression in psi'→psi2π is a consequence of the threshold factor contained in the Pomeron-2π coupling. The importance of the psi and psi' decays for the study of heavy mesonic resonances is stressed. (Auth.)