Prof John Cardy FRS

Abstract:

We investigate pomeron cut contributions in the triple-pomeron limit of one-particle inclusive cross sections, near t = 0 where the triple-pole coupling vanishes. We find that at t = 0 the cuts themselves are suppressed, contributing factors (lnM2)-2, rather than the single logarithms characteristic of cut contributions in two-body processes. We construct a simple reggeon calculus model in which all important cuts near t = 0 can be calculated, and suggest a simple way of parametrizing the data in that region. © 1973.

Abstract:

We study high energy elastic electron-electron scattering at wide angles in quantum electrodynamics. The amplitude is predicted to decrease exponentially with increasing energy, in agreement with strong interaction data. © 1969.

Abstract:

A reggeon calculus is derived from a hybrid perturbation-theory model using eikonal techniques. The resulting reggeon coupling functions have a simple form which enables many diagrams of interest to be evaluated explicitly. As an example, the properties of iterated Regge cuts are discussed and evaluated. Another important result is that the physical pomeron is not expected to have factorisable residues. © 1969.

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 Ø3 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.