Electromagnetic moments and transitions in nuclear density functional theory

We investigate the electromagnetic moments and transition properties of atomic nu-
clei within the framework of nuclear density functional theory (DFT). We focus on
presenting the role of pairing interaction, spontaneous symmetry breaking and sym-
metry restoration techniques in nuclear structure studies with particular emphasis
on their influence over electromagnetic multipole moments and transition strengths.
We present a self-complete theoretical framework covering the seniority and quasi-
particle formalisms of pairing, given by the Bardeen-Cooper-Schreiffer (BCS) and
Hartree–Fock–Bogoliubov (HFB) theories. Additionally, we cover the fundamentals
of DFT in the context of the atomic nucleus and symmetry restoration techniques
in the framework of the generator coordinate method (GCM). We also introduce the
phenomenology of multipole moments, transitions and spin isomerism from theoretical
and experimental perspectives.
We apply these topics to perform systematic self-consistent parameter-free calcu-
lations to describe odd-mass isotopic chains of yttrium and zirconium using the im-
plementations in the code HFODD. We calculate spectroscopic electric quadrupole
and magnetic dipole moments which are compared with available experimental data
resulting in overall good quantitative agreement. We analyse the effects of pairing,
deformation, blocking and time-odd components of the functionals. Additionally, we
calculate the transition strength and multipole moments of the isomeric and ground
states of 229Th using advanced beyond mean-field techniques and compare with recent
experimental data. Overall, this work implements and tests modern DFT approaches to
reproduce electromagnetic observables demonstrating them to provide a robust frame-
work to study the atomic nucleus across the nuclear chart.