Signature of Regge Cuts Coupled to Spinning Particles

Abstract

It is proved, by perturbation theory and by the method of Sudakov, that if two Regge poles with trajectories ${\alpha }_1$, ${\alpha }_2$ and signatures ${\tau }_1$, ${\tau }_2$ are exchanged, the resulting Regge branch point at $j={\alpha }_1+{\alpha }_2-1\mathrm{}$ appears only in partial-wave amplitudes of signature ${\tau }_1{\tau }_2\eta$, where $\eta =-1\mathrm{}$ if both Regge poles are fermions and $\eta =+1\mathrm{}$ otherwise. An example is given from the case of proton-proton scattering.