A relativistic eikonal description of nucleon propagation through nuclei

The main focus of my PhD thesis is on exclusive proton-induced A(p,pN) reactions. A relativistic and cross-section factorized framework for computing quasielastic $A(p,pN)$ observables is presented. To model the propagation of the nucleons through the nuclear medium, the eikonal approximation is used. Our eikonal model is very flexible as it can be used either in conjunction with relativistic optical potentials (relativistic optical model eikonal approximation, ROMEA) or within its Glauber multiple-scattering extension (relativistic multiple-scattering Glauber approximation, RMSGA). The major difference between both approaches is that the ROMEA framework describes the initial- and final-state interactions (IFSI) in terms of a nucleon-nucleus picture, whereas the RMSGA framework is essentially a nucleon-nucleon model. At lower nucleon energies, the former is preferred; while the latter is more suitable at higher energies. The ROMEA formalism has been put to a stringent test by comparing the calculations with A(p,pN) cross-section data from a wide variety of experiments. A fair description of the data is obtained, thereby demonstrating that the ROMEA model can be applied in a wide energy range. The RMSGA approach has been used to account for the IFSI in the study of A(p,2p) nuclear transparencies at GeV energies. To explain the oscillatory energy dependence of the nuclear transparency data, the A(p,2p) formalism has been extended to incorporate the Ralston-Pire model for the pp scattering amplitude and the concepts of color transparency (CT) and nuclear filtering (NF). Introducing the concept of NF brings the calculations in qualitative agreement with the data. Furthermore, the calculations indicate that CT is imperative to increase the predictions to the level of the data. The quantitative description of the data, however, is far from perfect and a number of uncertainties involving the A(p,2p) transparency remain. Finally, we have studied the accuracy of the eikonal approximation at lower energies by developing an extension of the ROMEA model which accounts for second-order eikonal corrections. The calculations show that the effect of the second-order eikonal corrections on A(e,e'p) observables is rather limited for Q^2 >= 0.2 (GeV/c)^2.

Grantor dc:publisher

Ghent University. Faculty of Sciences

Year dc:date

2007

Author dc:creator

• Van Overmeire, Bart

Contributors dc:contributor

• Ryckebusch, Jan

• Physics and Astronomy

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

und

Identifier

https://biblio.ugent.be/publication/468529
https://biblio.ugent.be/publication/468529/file/1879450

OAI identifier oai:identifier

oai:archive.ugent.be:468529