We consider a generalized interference model in which the Pomeron and the other Regge poles are built in the sense of a FESR bootstrap from both the resonance and background part of the low energy scattering amplitude. We develop a test of strong exchange degeneracy on the background part of the low energy scattering amplitude through the use of FESR. We show that the restrictions through FESR imposed by exchange degeneracy are weaker than those of duality. Finally, we are able to relate the amount of duality breaking in [Formula: see text] in the absence of exotic mesons to the ratio of NN or πN, P′, and ρ Regge residues.
The Breaking of Exchange Degeneracy and the Hadronic Selection Rules