High-energy protons

TL;DR: In this article, a review of high-energy proton-proton scattering experiments with high energy protons above 100 MeV is presented, where the phase shifts have not yet been determined unambiguously but the analyses have indicated the general trend and make it possible to test various models of the nucleon-nucleon interaction.

Abstract: Recent experiments with high-energy protons above 100 MeV are reviewed. Considerable data have been obtained from the study of proton-proton scattering below 400 MeV, especially where polarized beams have been used. It is now possible to extract the available information from such experiments by making phase shift analyses. The neutron-proton scattering experiments, although not so numerous, are reviewed where they are relevant to these analyses. The phase shifts have not yet been determined unambiguously but the analyses have indicated the general trend and make it possible to test various models of the nucleon-nucleon interaction. At energies above 400 MeV the character of the scattering changes and the production of mesons becomes noticeable. At the highest energies now available from the Bevatron at Berkeley antiprotons are produced. Many of the experimental results in proton-nuclear scattering have been explained in terms of nuclear transparency, optical and statistical models, but careful measurements of inelastic scattering have suggested that more detailed models are required. The polarization in elastic scattering can be explained by an optical model with the addition of a spin-orbit coupling similar to that used in the shell model. The theoretical variation of the polarization with scattering angle displays sharp features near the diffraction minima but the observation of these tends to be obliterated by finite experimental angular resolution and detection of inelastically scattered particles.