Some Comments on Testing Quantum Electrodynamics in Elastic Particle–Antiparticle Scattering

The photon propagator is assumed modified by the addition of a heavy photon of mass M and negative norm, in a conventional way of describing the possible breakdown of quantum electrodynamics. It is noted that because of interference between direct and annihilation diagrams, a dynamical zero can occur in the physical region of high energy elastic particle–antiparticle scattering, to lowest order in α. The position of this zero is a function of M. Several reactions are examined with a view to setting limits on M. The elastic scattering of transversely polarized e−e+ can be a sensitive probe for a finite M.