Donald R. Yennie

Some formal aspects of the Lamb shift problem

Abstract Renormalization theory for bound states in the Furry picture is developed and formal expressions for level shifts are derived. The justification of the scattering approximation for the fourth order Lamb shift, originally shown by Kroll and Mills, is confirmed by a more compact formal treatment.

Two-body QED bound states

The status of theory and experiment is reviewed for two-body systems in quantum electrodynamics, and places where further work would be useful are pointed out.

The hadronic structure of the photon and the space-time behavior of its interactions☆

Abstract The study of hadron-mediated high-energy photon interactions is continued, with emphasis on their space-time development. A formalism is developed which distinguishes these from direct photon interactions, and the concept of formation time is discussed. It is shown that hadron-mediated interactions have the appropriate long-range behavior required by the usual space-time treatment in accounting for the diffractive region. It is described how hadron-mediated interactions can lead to scaling (outside the context of specific models), and the relationship to the parton model is indicated.

Monopole excitations and elastic scattering

Abstract A simple relationship between elastic scattering amplitudes and monopole excitation amplitudes is pointed out and illustrated. It applies to potential scattering, and can be used for the nucleon-nucleus problem as well as electron-nucleus scattering. The example of scattering of electrons by carbon and calcium is used to illustrate the method.