γ-ray cascade decays from psi' (3684) to psi (3095)

The consequences of the existence of the γ-ray cascade decay psi' (3684) → γ + X and X → γ + psi (3095) are examined. The kinematics of the resulting 2γ mass spectrum together with the observed dynamics of the neutral missing mass in psi' (3684) → psi (3095) + neutrals are shown to be of such a form that a stringent upper limit can be placed on the sum of all such transitions