An examination of regge cut models in high energy scattering processes

Abstract

A phenomenolgical analysis of t-m body scattering data with particular emphasis on the phase and energy dependence overegged cut corrections is presented. After a brief summary of the Regge philosophy and approach, we survey the experimental data in chapter two. We note that all hadronic processes, as distinct from photoproduction appear to exhibit strong Regge shrinkage at large |t|. In chapter three, we motivate the eikonal model approach and show how it is used to calculate cuts in π N charge exchange and in photoproduction. Most of the phase problems encountered in the naive absorption models can be overcome, provided we use the true elastic amplitude (which we represent as a sum of P + P’ poles) to generate the absorptive corrections. We conclude this chapter by discussing how the shrinkage of the eikonal model cuts is inconsistent with the α(_eff)’s of chapter two for hadronic processes. We digress a little in chapter four to examine the important role played by t-channel unitarity and show how it can solve some of the problems outlined in the previous chapter by peaking the cut discontinuity at the position of the pole. Finally, we propose a new scheme for calculating Regge cuts and in the last chapter construct a specific model for π N CEX and π º photoproduction. A detailed examination of the cut discountinuity provides a possible explanation for the different energy dependence of these ostensibly similar processes. In conclusion, we discuss the implications of our model for the traditional (Michigan and Argonne) approaches to Regge cut phenomenology and suggest some areas which may provide interesting tests of the model.