Kinematic Superstructures for Abnormal Couplings in the8−πDual Amplitude

We present a general method for including abnormal couplings in multiparticle dual amplitudes. We construct amplitudes from a sum of terms having kinematic superstructure and dual substructure; and we show how a tensorial analysis of the kinematic superstructure in various channels determines the normality of the trajectories involved. As an illustration, we give a specific solution for abnormal couplings in the $8-\pi$ amplitude in which the above analysis is carried out in detail, and is compared with previous $6-\pi$ amplitudes and four-point amplitudes for spin-1-spin-0 scattering.