Conformal-Invariant Scattering Amplitude for Spinless Particles

Abstract
The implications of exact conformal symmetry for the S matrix of spinless massless particles are studied. Explicit forms for the scattering amplitudes are obtained in configuration space. Differential conditions for conformal-invariant amplitudes are derived in momentum space. These are solved for the case of elastic two-body scattering and lead to an integral representation of the general two-body amplitude in terms of Lorentz scalars. The integral representation involves two arbitrary functions of two variables and four explicit quadratures. Further study of the four quadratures appears in appendices.