Vector boson elastic scattering and Compton scattering

The most general Lorentz covariant scattering amplitude is constructed for the elastic scattering of neutral vector bosons and pions, using a symmetric spinor description for the vector particles. In the limit of zero mass for the vector boson, the known results for Compton scattering are reproduced in a simplified way that avoids discussion of gauge invariance. In this limit the scattering is generalized from photons to any massless particle. Finally, a brief discussion is given of the single-particle pole terms in Compton scattering. (author)