Isotope shifts for 1S0 - 3P0,1o Yb lines from multiconfiguration Dirac-Hartree-Fock calculations

Relativistic multiconfiguration Dirac-Hartree-Fock calculations with configuration interaction are carried out for the S-1(0) and P-3(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 S-1(0) - P-3(0)o (clock) and S-1(0) - P-3(1)o (intercombination) lines. We present improved estimates of the nuclear charge parameters lambda(A,A)' and differences in mean-square charge radii delta < r(2)>(A,A)' and examine the second-order hyperfine interaction for the 3Po 0,1 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.

Automated summary

Relativistic multiconfiguration Dirac-Hartree-Fock calculations were conducted for different states of neutral ytterbium, evaluating mass- and field-shift parameters and hyperfine interaction. Isotope shifts were estimated by multiple means to predict clock-line frequencies, with implications for nonlinear tests and signatures beyond the standard model.