The 6Li(e,e'p) and 142,146Nd(e,e'p) reactions

In this thesis two special cases of the (e,e'p) reaction are discussed. The first case is a (e,e'p) reaction for which the residual nucleus is unbound. With an unbound residual nucleus in the (e,e'p) reaction the proton-separation energy equals the two-body emission threshold of the target nucleus. Hence such a reaction is very interesting in a study of possible contributions of many-body mechanisms to cross sections obtained in (e,e'p) reactions. These contributions have been studied for the 6Li(e,e'p) reaction. The second case is an investigation of the change in shape of momentum distributions in the (e,e'p) reaction due to deformation effects, by studying proton knockout from 142Nd (spherical in the ground state) and 146N (deformable). The first part of the thesis deals with the 6Li(e,e'p) reaction. First the essential ingredients for the interpretation of the (e,e'p) cross sections are discussed. Three theoretical models, which predict the 6Li(e,e'p) spectral function, are discussed: the harmonic oscillator model shell, a three-body α-n-p cluster model, and another cluster model with different clusterization of the constituents 6Li and 5He. The experimental spectral function is presented and discussed within the theoretical framework. The occurence of reaction mechanisms beyond the quasi-elastic (e,e'p) reaction is investigated. In the second part the 142Ne(e,e'p) an 146Ne(e,e'p) reactions are discussed. The shape of the momentum distribution in deformed nuclei is discussed within the Nilsson model, followed by a summary of the experimental conditions under which the experimental spectral functions of both (e,e'p) reactions have been obtained. The energy-position and momentum distribution of the lowest discrete transitions are compared to the Nilsson-model predictions. (H.W.). 181 p.; 61 figs.; 27 tabs