Date of Award
Open Access Dissertation
Physics and Astronomy
There is a long-standing goal of understanding nuclear physics in terms of quarks and gluons, the constituent particles of nucleons. However, the underlying theory is strongly coupled at the scales relevant for nuclear physics; therefore, this goal can only be achieved through nonperturbative calculations. Additionally, nuclear targets are employed in a variety of experiments ranging from electroweak processes to Beyond the Standard Model physics. Thus, it is important to have a strong theoretical foundation for nuclear physics in the presence of external fields in order to interpret experimental results. Effective field theory (EFT) for nuclear physics constitutes a systematic and model-independent approach to performing the necessary calculations to achieve this understanding in a manner that is consistent with the symmetries of quantum chromodynamics (QCD), the theory of the strong interactions. Yet, an EFT contains a priori undetermined coefficients that must be obtained either from data or from nonperturbative calculations. In the absence of these determinations, it is imperative to constrain the coefficients through other means. Here, the large-Nc limit of QCD, where Nc is the number of colors, is combined with nuclear EFTs to derive such constraints for one and two nucleons in external fields. A general set of constraints for the nuclear currents is derived, and these constraints are applied to the particular cases of electroweak currents, neutrinoless double β decay in the context of the light Majorana exchange mechanism, and the direct detection of dark matter.
Richardson, T.(2021). Large-Nc Constraints for One- and Two-Nucleon Currents in Effective Field Theory. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/6466