Doctor of Philosophy (Ph.D.)
John D Walecka
The applicability of a new approach, developed by Furnstahl, Serot and Tang, to describe the nuclear many-body system is studied for nuclei far from stability. This approach combines elements of effective field theory (EFT) and density functional theory (DFT) and has already been tested in the stability region. In this thesis, several steps are taken to address the question of the applicability of the EFT/DFT formulation to nuclei far from stability. First the convergence of the approach is studied by applying it directly to selected doubly-magic nuclei far from stability. An independently developed code, which can incorporate various levels of approximation of the chiral effective lagrangian, is used to solve the self-consistent relativistic Hartree equations. This program is used to obtained results for ground-state properties such as binding energies, single-particle level structure, and densities of the doubly-magic nuclei 132,100Sn and 48,78Ni. Second, the accuracy of the calculation of the ground-state density is indirectly studied by using the single-particle (Kohn-Sham) wave functions to calculate weak transitions. The weak currents used correspond to the Noether currents derived from the effective lagrangian. The calculations use a general expression for single-particle transition matrix elements, derived here, from which any semi-leptonic weak rate can be calculated. Attention is focused on beta-decay processes in nuclei neighboring 132Sri and the results are compared with available experimental data. Finally calculations are extended to determine total binding energies and single-particle and single-hole binding energies, spins, and parities for isotopes with magic numbers N = 28, 50, 82, 126, and isotopes with Z = 28, 50, 82. The results of this thesis indicate that the EFT/DFT formulation of Furnstahl, Serot and Tang is capable of reproducing the relevant ground-state binding energies to within 1%, chemical-potentials with an average accuracy of 10%, and ground-state spins and parities, at least if the neutron level density is not too high.
© The Author
Huertas Chacon, Marco Antonio, "Applications of effective field theory/density functional theory to ground-state properties of nuclei far from stability" (2003). Dissertations, Theses, and Masters Projects. Paper 1539623424.