Coulombic-hadronic interference in an eikonal model

Abstract

The problem of extracting the phase of the hadronic proton-proton scattering amplitude from its interference with the Coulombic amplitude near the forward direction is re-examined using an eikonal model. The results are in accord with the Feynman diagrammatic calculation of West and Yennie, with some small corrections. An especially compact forms is derived for the electromagnetic shift in the hadronic amplitude's phase, which includes the effect of the electromagnetic form factor. The largest modification of the previous results comes from the effect of the form factor on the phase of the electromagnetic amplitude itself.