FESR constraint on baryonium resonances

The S, T, U resonance contribution to the p̄p FESR is an order of magnitude smaller than the ω Regge contribution. Within the duality scheme for baryoniums this would imply either a large renormalisation of the ωp̄p Regge coupling (by a factor of ~ 3) by nonplanar unitarity effects or that there are a host of other broad baryonium states hiding in the S, T, U region. The first alternative seems to be disfavoured, however, by other phenomenological constraints.