Relations among the Superconvergence Conditions for Forward Elastic Scattering. II. Linear Relations among the Crossed-Channel Helicity Amplitudes

The relations among the superconvergence conditions for the forward elastic scattering of two particles with spin are discussed. Because of the existence of identities among the $t$-channel helicity amplitudes at $t=0$, the corresponding superconvergence conditions are not independent. It is shown that there exists a set of $t$-channel helicity amplitudes with the following properties: (1) The corresponding superconvergence conditions are independent; (2) the superconvergence conditions for any other $t$-channel helicity amplitude are linearly related to the superconvergence conditions for this set of amplitudes.