High energy scattering

Abstract

This thesis is primarily concerned with the Absorption Model for high energy scattering, and in particular the application of the Absorption Model to the processes Nucleon-Nucleon charge exchange, and Nucleon-Antinucleon charge exchange. In the first chapter, a review of the development of the one particle exchange model of high energy scattering is given. The difficulties of the earlier applications are discussed, and the role of absorptive corrections in resolving these difficulties is outlined. In Chapter 2, the mathematical framework for adding absorptive corrections to one particle exchange contributions is given. The original prescription due to Sopkovich is discussed, and recent approaches to the problem are reviewed. In Chapter 3, the Absorption Model is applied to the process of neutron-proton backward scattering, or charge exchange. It is found that one-pion exchange In the Absorption Model gives a good fit to the charge exchange peak at small angles, but there is disagreement with experiment at large angles. Rho-meson exchange Is found to be unsatisfactory. The energy dependence of one-meson exchange In the Absorption Model Is Investigated. In Chapter 4, the Absorption Model Is applied to Nucleon-Antlnucleon charge exchange. Good agreement with experiment is obtained. The sensitivity of the results to the precise model of elastic scattering is investigated. In Chapter 5, we discuss various refinements to our work in Chapter 3, to see if better large angle results can be obtained. In our concluding chapter, the Absorption Model is compared with the Regge pole exchange model, and the possibility of combining the two approaches is discussed.