Diffraction Scattering for Inelastic Processes

Previous treatments on high-energy scattering in quantum electrodynamics are extended to diffractive inelastic processes. We explore the model in which the diffractive excitation proceeds through the exchange of vector mesons. Six inelastic impact factors are explicitly calculated in the lowest order: (1) scalar to scalar, (2) pseudoscalar to pseudoscalar, (3) vector to vector, (4) axial vector to axial vector, (5) scalar to axial vector, and (6) pseudoscalar to axial vector. For all six of these impact factors, the masses of the incoming and outgoing particles may be different; and for the last two impact factors, the spins and the parities of the incoming and outgoing particles may be different. The nonvanishing of the impact factors demonstrates that mass, spin, and parity can change during a diffractive process. We also conclude that $C$ (charge conjugation quantum number), $S$ (strangeness), $I$ (isotopic spin), $B$ (baryon number), and $G$ parity, etc., must remain the same during a diffractive process. Some general properties of the impact factor are also discussed.