The diffraction pattern of pp elastic scattering and the composite structure of the proton

Abstract

The consequences of the quark-glue structure of hadrons for pp elastic scattering are examined in a simple model where the glue is taken to be the active constituent in normal (low p T) hadronic collisions. Earlier work based on the study of pp inelastic diffraction led to the conclusion that the glue-glue elastic amplitude t g is approximately Gaussian in the glue-glue impact parameter b g, with maximum opacity at b g = 0. A slight refinement of this approximation, in which t g is almost maximally opaque over a small b g interval and is Gaussian at larger b g, is now shown to account for the remarkable diffraction structure observed in pp elastic scattering at ISR energies. A very simple form is obtained for the form factor describing the impact parameter distribution of the glue inside a proton relative to the proton itself.