Invariant-Amplitude Approach toO(3, 1)Symmetry of Regge Trajectories

A simple method is given for constructing the leading terms which arise from the exchange of a single Lorentz pole [$O(3, 1)$ conspiracy of Regge poles] in the case of high-energy forward scattering of equal-mass particles. It is shown that some of the results may be taken over for the unequal-mass case; in particular, that the $s^{\alpha }$ term in forward scattering arising from an $M=0\mathrm{}$ conspiracy is pure spin-non-flip, while that from an $M=1\mathrm{}$ conspiracy is pure spin-flip.