COMPTON-SCATTERING IN THE LIGHT-CONE TAMM-DANCOFF APPROXIMATION

The Tamm-Dancoff approximation is used to study Compton scattering in light-cone-quantized QED. The charge-one sector is considered in a two-particle truncated Fock space. The problem is exactly solvable and it is shown that the internal photon propagator develops a singularity similar to the one reported by Krautgartner, Pauli, and Wolz in the light-cone calculation of positronium. This singularity depends on the external energy and therefore cannot be removed by conventional counterterms.