REPRESENTATIONS OF EUCLIDEAN GROUP E2 IN DESCRIPTION OF UNEQUAL MASS SCATTERING AMPLITUDES

We have expressed the t = 0 unequal mass scattering amplitude, in terms of irreducible representations of the group E2, the light-like little group of the inhomogeneous Lorentz group. The representation exhibits neatly the analytic properties of the scattering amplitude without the difficulties of the usual Regge pole analysis around cos θt = 1, at t = 0 unequal mass scattering. Various characteristic features of the representation, as the exponential or oscillatory asymptotic behaviour in s are discussed for their theoretical and experimental implications. © 1969.