Suppression ofψphotoproduction

We estimate the contribution to $\psi$ photoproduction from its conventional hadronic components by using an $\epsilon$-exchange model. The results, which are too small, are compared with the parallel ${\rho }^{\prime }$ case. A reduction factor is observed which also plays an important role in other models. We discuss, in particular, its occurrence in a peripheral model which assumes dominance of new states in the $\psi$ fragmentation vertex which interact strongly with conventional hadrons. The strong reduction factor follows from the mismatch between production thresholds and particle masses. Its role is discussed at length and compared with different points of view.