Amplitudes for ϱ and A2 Regge exchanges in δ production processes

In δ production processes like $\text{π}{}^{\mathrm{+}}\text{p}\text{→ π}{}^0\text{δ}{}^{\mathrm{++}}\text{,}\text{K}{}^{\mathrm{+}}\text{p}\text{→}\text{K}{}^0\text{δ}{}^{\mathrm{++}}\text{,}\text{K}{}^{\mathrm{?}}\text{n}\text{→}\text{K}{}^0\text{δ}{}^{\mathrm{?}}$, exchange degeneracy breaking between ? and A₂ Regge poles is shown to be present in all s-channel helicity amplitudes including the double-flip one. Once. the dominance of two among four amplitudes and SU(3) invariance are assumed, the amplitudes are obtained in a rather model-indenpendent way. The peculiar feature of these amplitudes are analyzed and in particular some evidence for universality in the impact parameter representation is pointed out. Possible explanations are proposed.