Electromagnetic processes induced by electron scattering off few-nucleon systems are theoretically investigated in the non-relativistic formalism. Non-relativistic one-body nuclear current operators are used with a parametrization of nucleon electromagnetic form factors based on recent experimental nucleon scattering data. Electromagnetic form factors of three-nucleon and four-nucleon systems are calculated from elastic electron-nucleus scattering information. Nuclear response functions used in the determination of differential cross sections for inclusive and exclusive quasi-elastic electron-nucleon scattering from the 4He nucleus are also calculated. Final-state interactions in the quasi-elastic nucleon knockout process are explicitly taken into account using the Glauber approximation. The sensitivity of the response functions to the final-state interactions is investigated. The Antisymmetrized Molecular Dynamics approach with angular momentum and parity projection is employed to construct ground state wave functions for the nuclei. A reduced form of the realistic Argonne V18 nucleon-nucleon potential is used to describe nuclear Hamiltonian. A convenient numerical technique of approximating expectation values of nuclear Hamiltonian operators is employed. The constructed wave functions are used to calculate ground-state energies, root-mean-square radii and magnetic dipole moments of selected light nuclei. The theoretical predictions of the nuclear properties for the selected nuclei give a satisfactory description of experimental values. The Glauber approximation is combined with the Antisymmetrized Molecular Dynamics to generate wave functions for scattering states in quasi-elastic scattering processes. The wave functions are then used to study proton knockout reactions in the 4He nucleus. The theoretical predictions of the model reproduce experimental observation quite well. / Physics / Ph D. (Physics)

Electromagnetic processes induced by electron scattering off few-nucleon systems are theoretically investigated in the non-relativistic formalism. Non-relativistic one-body nuclear current operators are used with a parametrization of nucleon electromagnetic form factors based on recent experimental nucleon scattering data. Electromagnetic form factors of three-nucleon and four-nucleon systems are calculated from elastic electron-nucleus scattering information. Nuclear response functions used in the determination of differential cross sections for inclusive and exclusive quasi-elastic electron-nucleon scattering from the 4He nucleus are also calculated. Final-state interactions in the quasi-elastic nucleon knockout process are explicitly taken into account using the Glauber approximation. The sensitivity of the response functions to the final-state interactions is investigated. The Antisymmetrized Molecular Dynamics approach with angular momentum and parity projection is employed to construct ground state wave functions for the nuclei. A reduced form of the realistic Argonne V18 nucleon-nucleon potential is used to describe nuclear Hamiltonian. A convenient numerical technique of approximating expectation values of nuclear Hamiltonian operators is employed. The constructed wave functions are used to calculate ground-state energies, root-mean-square radii and magnetic dipole moments of selected light nuclei. The theoretical predictions of the nuclear properties for the selected nuclei give a satisfactory description of experimental values. The Glauber approximation is combined with the Antisymmetrized Molecular Dynamics to generate wave functions for scattering states in quasi-elastic scattering processes. The wave functions are then used to study proton knockout reactions in the 4He nucleus. The theoretical predictions of the model reproduce experimental observation quite well. / Physics / Ph D. (Physics)

Nous présentons une approche alternative aux diagonalisations exactes de calculs en modèles en couches pour l'étude microscopique de la structure nucléaire. Nous avons tout d'abord minimisé l'énergie totale du système par la résolution des équations Hartree-Fock dans la base définie par l'espace de valence du modèle en couches. Nous avons finalisé la mise au point de ce programme par comparaison des résultats avec les solutions de problèmes solubles analytiquement comme ceux d'un hamiltonien SU(3) ou par comparaison avec des diagonalisations exactes du modèle en couches. Ensuite, nous avons mis au point des procédures pour l'obtention de ces mêmes calculs avec contraintes pour une description complète de la surface d'énergie potentielle d'un noyau donné en fonction des degrés de liberté Q20 et Q22. La restauration du moment angulaire par méthode de projections a permis d'obtenir les spectres des noyaux rotationnels dans le cas axial et dans le cas triaxial. Enfin, la méthode des coordonnées génératrices a permis le mélange de ces déterminants de Slater non orthogonaux. Parmi les différentes applications, nous avons pu décrire les noyaux déformés le long de la ligne N=Z autour du80Zr ou un nouvel îlot d'inversion à N=50. / We present an alternative approach to shell diagonalizations for microscopic description of nuclear structure. First we minimized the total system energy solving the Hartree-Fock equations within the shell model valence space. The results are compared with exact shell model diagonalization and an exact soluble SU(3) hamiltonian. Then, we developed procedures to obtain the same of type calculations with constrained conditions on the quadrupole degrees of freedom to obtain the full potential energy surfaces. The angular momentum restauration was obtained through projection method to generate rotionnal spectra of nuclei in both axial and triaxial cases. Finally the generate coordinate method was applied to mix several of these non-orthogonal Slater determinants. Among several applications we managed to describe deformed nuclei along the N=Z line around 80Zr or a new island of deformation at N=50. Finally, a first application in the superheavy region predicts a spherical gap for the Z=114, N=184 isotope