Theoretical study of some experimentally relevant states of dysprosium

Abstract

Configuration interaction method is used to calculate transition amplitudes and other properties of the low states of dysprosium which are used in cooling and in study of the time variation of the fine structure constant and violation of fundamental symmetries. The branching ratio for the cooling state to decay to states other than ground state is found to be smaller than 10 −4 . The matrix element of the weak interaction between degenerate states at E = 19797.96 cm −1 is about 2 Hz which is consistent with the experimental limit |HW | = |2.3 ± 2.9(statistical) ± 0.7(systematic)| Hz [A. T. Nguyen, D. Budker, D. DeMille, and M. Zolotorev, Phys. Rev. A 56, 3453 (1997)] and points to feasibility of its experimental measurement. Applications include search for physics beyond the standard model using the PNC isotopic chain approach.

Dynamic polarizabilities and magic wavelengths for dysprosium

“…(1) in which we substitute transition amplitudes found from the CI calculations [5] and experimental energies. We use theoretical values in the few cases where experimental energies are not available.…”

“…Summation goes over complete set of excited states n. We use the relativistic configuration interaction (CI) technique described in our previous papers [5,11,23] to perform the calculations. The single-electron and manyelectron basis sets, the fitting parameters and other details of present calculations are exactly the same as in Ref.…”

“…This is a heavy atom which has many stable Bose and Fermi isotopes (from A = 156 to A = 164) and a pair of almost degenerate states of opposite parity at E=19798 cm −1 . These features were used in study of the parity non-conservation (PNC) [1][2][3][4][5] and possible time-variation of the fine structure constant [6][7][8][9][10][11][12].…”

Stark shift and parity nonconservation for near-degenerate states of xenon

“…The experimental value for Dy is |W AB | = |2.3 ± 2.9 ± 0.7| Hz [3], while the theoretical value is W AB = 4(4) Hz [15]. Note that highly excited np 1/2 states give significant contribution to the value (8) for the weak matrix element for Xe, making it smaller.…”

Magnetic hyperfine structure of the ground-state doublet in highly charged ionsTh89+,87+229and the Bohr-Weisskopf effect

“…Here one can mention a refinement of some fundamental laws and symmetries of Nature, for example, the CP-violation, the variation of the fine structure constant [28,29,[35][36][37], the local Lorentz invariance and the Einstein equivalence principle [38]. Unusual for traditional nuclear physics decay channels of the isomeric state -the electron bridge [17,39] and nuclear light [25][26][27] -probably imply that the 3/2 + (7.8 ± 0.5 eV) state can be occupied by laser emission through nuclear photo-excitation process [20,27] or inverse electron bridge [20,40,41].…”