Evaluation of folded diagram effective interactions and the microscopic calculation of dynamical effects in finite nuclei

The microscopic folded diagram many body perturbation theory and its application to the calculation of effective interactions for light nuclei (A = 17 and A = 18) are the subject of the first part of this work. In the calculation of the single particle energies in 17O and 17F the inclusion of folded diagrams is very important; it is equivalent to a self-consistent determination of the Q-box starting energy. We have included core polarization processes in our calculation and studied the effects of extended model spaces. Our investigation was based on the Reid soft-core and Bonn-Juelich potentials. Good agreement with the experimental single particle spectra is found. The systematic small discrepancy in the Coulomb energy difference δE/sub c/, however, could not be removed. We have performed structure calculations for the low-lying excitations in 18O and 18F and reexamined the intermediate-state convergence problem for the core polarization diagram G/sub 3plh/. The resulting spectra of 18O and 18F are reproduced best, in the folded diagram perturbation theory, with the meson exchange Bonn-Juelich potential. In the second part of this work we investigate dynamical effects in finite nuclei and their relation to the calculation of giant multipole resonances. The single particle and hole energies to be used in a calculation of highly excited states are generally different from their experimental values. In order to study these effects we present and compare two microscopic theories, the folded diagram perturbation theory and the Green's function formalism