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Charge conjugation parity ($CP$) symmetry violation is linked to important physics questions such as the matter-antimatter asymmetry and the Strong $CP$ Problem. Tabletop precision measurements using heavy atoms and molecules can set stringent bounds on the new physics that attempt to explain these problems, and these measurements are complementary to direct searches of new particles using colliders. Radium, among other radioactive elements, is a sensitive probe to hadronic $CP$ violation due to its heavy and octupole-deformed nucleus, and the sensitivity is further enhanced by incorporating the radioactive element in a molecule. In this thesis we introduce the first laser cooling of radium-226 ions and measurements of the low-lying $^{226}$Ra$^+$ energy levels. We realize control of the radium ion $S_{1/2}\rightarrow D_{5/2}$ optical qubit for implementing the quantum logic spectroscopy technique to prepare and readout the radioactive molecular ions. We also present production and detection of radium-containing molecular ions that are sensitive to hadronic $CP$ violation. Finally, we discuss ongoing work on designing a hadronic $CP$ violation experiment using radioactive molecular ions and developing a long-term source for the short-lived radium-224 and radium-225 atoms.

Submitted by Sheila MONTEIRO (sheila.monteiro@ufma.br) on 2020-01-28T13:21:01Z No. of bitstreams: 1 JONAS-ARAUJO.pdf: 1968979 bytes, checksum: 63e2a0bae286dc601d76499e0bd15d7d (MD5) Made available in DSpace on 2020-01-28T13:21:01Z (GMT). No. of bitstreams: 1 JONAS-ARAUJO.pdf: 1968979 bytes, checksum: 63e2a0bae286dc601d76499e0bd15d7d (MD5) Previous issue date: 2019-03-11 In this work we investigate electric dipole moments (EDMs) and magnetic dipole moments (MDMs) in scenarios with Lorentz symmetry violation (LV). We begin by generally describing the standard model and the EDMs and MDMs in the usual case, as well as the Schiff’s theorem, which poses difficulties in their detection. After this, we explore the effects of nonminimal couplings, arising from the tensor (kF )μ⌫↵# of the CPT-even electrodynamics of the standard model extension (SME), in the Dirac equation on the EDMs and MDMs, besides pondering the generated terms’ detectability. The sidereal analysis of the LV terms is also performed. Next, we repeat this investigation over a class of nonminimal couplings that generate EDM and MDM via a tensor Tμ⌫, with no symmetry in its indices at first. The possible couplings are put forward in hermitian forms and proposals for detection are made. Following this, we considered a modified Coulomb potential and calculated its effect on the Schiff moment: a residual interaction term that circumvents the shielding (predicted by the Schiff’s theorem) due to the atomic nucleus’ finite size. We concluded that the residual term absorbs the modified Coulomb potential’s anisotropies, which are due to the Lorentz symmetry violation in the SME’s CPT-even electrodynamics. In the next chapter, we considered another source of EDM: P- and T-odd couplings between electrons and nucleons (protons and neutrons). After outlining how to obtain the EDM contribution from a coupling in the usual case, we listed general classes of couplings with LV tensors of rank-1 to rank-2. Once these were listed, classified according to their behavior under C, P and T, and applyied the nonrelativistic limit for the nucleons, their EDMcontributions were calculated and their magnitudes limited according to recent experimental data. Whenever applicable, the sidereal analysis was performed on terms with spatial indices in the LV tensors. Neste trabalho investigamos momentos de dipolo elétrico (EDMs) e magnético (MDMs) em ambientes com violação da simetria de Lorentz (LV). Num primeiro momento, expomos o modelo padrão e os EDMs e MDMs no cenário usual, bem como o teorema de Schiff − que impõe dificuldades na detecção de EDMs. Feito isto, exploramos as consequências de acoplamentos não mínimos, advindos do tensor (kF )μ⌫↵# da eletrodinâmica par sob CPT do modelo padrão estendido (MPE), na equação de Dirac sobre EDMs e MDMs e ponderamos quanto à detectabilidade dos termos gerados. É feita também a análise sideral dos termos LV. Depois disto, repetimos a análise para uma classe de acoplamentos não mínimos que geram EDM e MDM a partir de um tensor Tμ, a princípio sem simetrias. Os acoplamentos possíveis são escolhidos em suas formas hermitianas e propostas para detecção são feitas. Em seguida, consideramos um potencial de Coulomb modificado e calculamos seu efeito sobre o momento de Schiff: um termo de interação residual que burla a blindagem (prevista pelo teorema de Schiff) devido às dimensões do núcleo atômico. Observa-se que o termo residual absorve as anisotropias do potencial de Coulomb modificado, que advém da violação da simetria de Lorentz na eletrodinâmica do MPE. No capítulo seguinte, consideramos outra fonte de EDM: acoplamentos P-e T-ímpares LV não mínimos entre elétrons e núcleons (prótons e nêutrons). Neste, depois de ilustrar como obter o EDM de um acoplamento no cenário usual, listamos classes gerais de acoplamentos com tensores LV de rank-1 a rank-4. Depois de listados, classificados sob C, P e T, e aplicado o limite não relativístico aos núcleons, calculou-se as contribuições EDM e usou-se dados experimentais recentes para impor bounds nos coeficientes LV. Quando necessário, fez-se a análise sideral dos termos com índices espaciais nos tensores LV.

A nuclear-structure campaign has been initiated to investigate the isotopes of Hg around mass 199. To date, 199Hg provides the most stringent limit on an atomic electric dipole moment (EDM). Standard Model predictions of the EDM in 199Hg are many orders of magnitude below current experimental reach. There are, however, many models beyond the Standard Model, such as multiple-Higgs theories and supersymmetry, that generally predict much larger EDMs within experimental reach. The observation of a large permanent EDM would represent a clear signal of CP violation from new physics outside the Standard Model. Theoretical nuclear-structure calculations for 199Hg are challenging, and give varied predictions for the excited-state spectrum. Understanding the E2 and E3 strengths in 199Hg will make it possible to develop a nuclear-structure model for the Schiff strength based on these matrix elements, and thereby constrain present models that predict the contribution of octupole collectivity to the Schiff moment of the nucleus. One of the most direct ways of measuring the matrix elements connecting the ground state to excited states is through inelastic hadron scattering. The high level density of a heavy odd-A nucleus like 199Hg makes a measurement extremely challenging. Complementary information can, however, be determined for states in the neighbouring even-even isotopes of 198Hg and 200Hg, and single-nucleon transfer reactions on targets of even-even isotopes of Hg can yield important information on the single-particle nature of 199Hg. The work presented here is the result of two experiments which used a 22-MeV deuteron beam incident on an isotopically enriched target of 200Hg32S. These experiments were performed using the Q3D magnetic spectrograph at the Maier-Leibnitz Laboratory, in Garching, Germany. The first experiment was an inelastic deuteron scattering experiment, 200Hg(d,d’)200Hg, populating 97 states up to an excitation energy of 4.2 MeV. Fifty-four states were newly discovered. Deformation parameters were extracted through coupled-channel calculations with global optical-model potential (OMP) parameter sets. The total B(E3; 0+ to 3-) strength in this region was estimated to be 0.55+0.12-0.18 e2b3, where the reported errors represent the upper and lower limits. The second experiment was a single-nucleon transfer reaction into 199Hg, 200Hg(d,t)199Hg, up to an excitation energy of 3 MeV. In total, 91 excited levels were identified, including fifty newly observed levels in this work. Spin-parity assignments and spectroscopic factors were extracted through distorted-wave Born approximation calculations with global OMP sets. The results from these two experiments are presented and further discussed in this thesis. Natural Sciences and Engineering Research Council of Canada