Isotope shifts for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>S</mml:mi><mml:mn>0</mml:mn><mml:none/><mml:mprescripts/><mml:none/><mml:mn>1</mml:mn></mml:mmultiscripts><mml:mo>−</mml:mo><mml:mmultiscripts><mml:mi>P</mml:mi><mml:mrow><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mi>o</mml:mi><mml:mprescripts/><mml:none/><mml:mn>3</mml:mn></mml:mmultiscripts></mml:mrow></mml:math> Yb lines from multiconfiguration Dirac-Hartree-Fock calculations
Jesse S. Schelfhout, John J. McFerran
Abstract
Relativistic multiconfiguration Dirac-Hartree-Fock calculations with configuration interaction are carried out for the $^{1}S_{0}$ and $^{3}P_{0,1}^{o}$ states in neutral ytterbium by use of the available grasp2018 package. From the resultant atomic state functions and the ris4 program, we evaluate the mass- and field-shift parameters for the $^{1}S_{0}\ensuremath{-}\phantom{\rule{0.16em}{0ex}}^{3}P_{0}^{o}$ (clock) and $^{1}S_{0}\ensuremath{-}\phantom{\rule{0.16em}{0ex}}^{3}P_{1}^{o}$ (intercombination) lines. We present improved estimates of the nuclear charge parameters ${\ensuremath{\lambda}}^{A,{A}^{\ensuremath{'}}}$ and differences in mean-square charge radii $\ensuremath{\delta}{\ensuremath{\langle}{r}^{2}\ensuremath{\rangle}}^{A,{A}^{\ensuremath{'}}}$ and examine the second-order hyperfine interaction for the $^{3}P_{0,1}^{o}$ states. Isotope shifts for the clock transition have been estimated by three largely independent means from which we predict the unknown clock-line frequencies in bosonic Yb isotopes. Knowledge of these line frequencies has implications for King-plot nonlinearity tests and the search for beyond-standard-model signatures.