| Quantum Chromodynamics (QCD) is believed to govern the strong interactions and is therefore the theory underlying nuclei. The basic constituents of the theory are quarks and gluons. In the lower-energy regime, these form bound states to produce the observed hadronic and nuclear spectra. Unfortunately, the task of solving this bound-state problem directly from QCD is complicated and is not currently feasible in applications to nuclei.; The complicated nature of QCD led many to continue work on Quantum Hadrodynamic (QHD) models of nuclei based on the more convenient hadronic degrees of freedom. Traditionally, the models were built upon a renormalizable field theory with nucleons interacting through simple meson exchange. The original QHD models, however, encountered difficulty due to large vacuum-loop effects. Also, the models had little connection to QCD.; The modern perspective of effective field theory (EFT), however, provides a consistent framework for constructing a theory of QCD based on observed hadronic degrees of freedom. This framework has already been successfully and systematically applied to the study of vacuum processes; this motivates the application of EFT concepts to the study of nuclei. Models based on EFT offer a new interpretation of traditional QHD models.; A comprehensive analysis (at the mean-field level) of effective QHD models based on a meson-exchange phenomenology was first presented by Furnstahl, Serot, and Tang. In this work, we present an alternative approach, developing a formalism based on point-coupling (contact) interactions of the nucleons. In comparison to mesonic models, little work has been done regarding point-coupling models of nuclei and we present the first comprehensive study of these models as effective field theories of nuclei. The foundation for a full loop expansion of the model is mean-field theory, and before a full loop expansion can be explored, the mean-field results must first be tested on their own merit. The show that the proper systematics exist at the mean-field level, and that EFT concepts can be profitably applied to models of nuclei. We also create the tools to test the theory beyond the mean-field approximation. |
