Doctoral Dissertations

Date of Award

12-2015

Degree Type

Thesis

Degree Name

Doctor of Philosophy

Major

Physics

Major Professor

Thomas Papenbrock

Committee Members

Lucas Plater, Kate Jones, Robert Hinde

Abstract

Collective motion in heavy nuclei has been studied within collective and algebraic models, and within density functional theory. While they reproduce the energy spectra of these systems, their predictions for some electromagnetic transitions and moments do not lie within experimental uncertainty; in other words, these predictions are inconsistent with experimental data. An effective field theory approach to collective motion in heavy nuclei solves this long standing problem. Based on symmetry arguments only, the effective field theories, constructed as expansions in powers of a small parameter, consistently describe the energy spectra of nuclei exhibiting collective motion at low order in the expansion parameter, reproducing results from models at this order. The systematic construction of operators associated with observables, allows for the estimation of theoretical uncertainties order by order. This is a highlight of effective field theories. Bayesian methods can be employed to quantify these uncertainties, providing them with a clear statistical interpretation. Within the effective field theories, the description of experimental data on electric quadrupole transitions and moments is consistent within theoretical uncertainties. In nuclei near shell closures, the systematic construction of the electric quadrupole operator allows for the description of sizeable static quadrupole moments and transitions between states with the same phonon number. In rotational nuclei faint transitions between states in different rotational bands are correctly described and are of natural size.

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