Prof John Cardy FRS

Abstract:

The eikonal approximation is extended to arbitrary Feynman diagrams, in a renormalised spinless theory. A set of rules is formulated, which gives the eikonal expression for any given set of diagrams. Features reminiscent of a parton model emerge. © 1969.

Abstract:

A study is made of the high-energy behaviour of the elastic two-particle amplitude at fixed scattering angle, in both a simple س model, and in quantum electrodynamics. In the first case, diagrams associated with the Born terms are shown to dominate. In the second, electron-electron scattering is shown to exhibit a power-law dependence on the energy, more rapidly decreasing than that of the Born terms alone. © 1969.