PhD Thesis

Abstract

The study of physics beyond the Standard Model is on the frontier of modern physics. Any detection of these phenomena will be paradigm shifting for our understanding of fundamental physics. Signatures of these phenomena are expected to manifest in low energy systems allowing the use of low energy experiments to constrain possible new physics to large degrees. Using the deformed Nilsson model and Schmidt model, several second order tensor properties are calculated in nuclei. These are enhanced by the collective quadrupole deformation of the nucleus. Specifically, the quadrupole moment of neutron distribution, Q_n, the weak quadrupole moment, Q_W⁽²⁾, the Lorentz invariance violating energy shift, δ <H>, and the magnetic quadrupole moment of the nucleus, M are calculated. The weak quadrupole moment introduced in this thesis is a nuclear property which produces a tensor weak interaction between the nucleus and electrons and can be observed in atomic and molecular experiments measuring parity nonconservation. The values of Q_n, Q_W⁽²⁾, δ <H> and M are calculated for the nuclei ⁹Be, ²¹Ne , ²⁷Al, ^{151, 153}Eu, ¹⁶³Dy, ¹⁶⁷Er, ¹⁷³Yb, ^177,179Hf, ¹⁸¹Ta, and ²²⁹Th. The values of Q_n, $Q_W⁽²⁾, δ <H> for nuclei ¹³¹Xe, ¹³³Cs, ²⁰¹Hg are also calculated. The resultant magnetic quadrupole moment energy shifts in diatomic molecules are calculated for ¹⁷³YbF , ^177,179HfF⁺, ¹⁸¹TaN, ¹⁸¹TaO⁺, ²²⁹ThO and ²²⁹ThF⁺.

Also presented are the results of relativistic many-body calculations predicting properties of open 6d-shell superheavy elements dubnium (Db, Z=105), seaborgium (Sg, Z=106), bohrium (Bh, Z=107), hassium (Hs, Z=108) and meitnerium (Mt, Z=109), and the superheavy noble element oganesson (Og, Z=118). These calculations were performed using an efficient version of the ab initio method including the configuration interaction combined with perturbation theory for the distant states effects. For these elements the energy levels, ionisation potentials, isotope shifts and strong electric dipole transition amplitudes were calculated. Comparison with lighter analogs reveals significant differences due to strong relativistic effects in superheavy elements. Very large spin-orbit interaction distinguishes subshells containing orbitals with definite total electron angular momentum j. This effect replaces Hund's rule in lighter elements. Calculations of Ta and Rn, lighter analogs of Db and Og, are compared to experiment with good agreement.