Relativistic calculations of the isotope shifts in highly charged Li-like ions

Relativistic calculations of the isotope shifts of energy levels in highly charged Li-like ions are performed. The nuclear recoil (mass shift) contributions are calculated by merging the perturbative and large-scale configuration-interaction Dirac-Fock-Sturm (CI-DFS) methods. The nuclear size (field shift) contributions are evaluated by the CI-DFS method including the electron-correlation, Breit, and QED corrections. The nuclear deformation and nuclear polarization corrections to the isotope shifts in Li-like neodymium, thorium, and uranium are also considered. The results of the calculations are compared with the theoretical values obtained with other methods.

Figure 1

Feynman diagrams representing the lowest-order nuclear recoil corrections. The dotted line denotes the Coulomb recoil interaction that leads to the $\mathrm{NMS}$ and $\mathrm{SMS}$ contributions; the dashed line indicates the one-transverse-photon recoil interaction that leads to the $\mathrm{RNMS}$ and $\mathrm{RSMS}$ contributions.

Figure 2

Feynman diagrams representing the interelectronic-interaction corrections of the first order in $1/Z$ to the NMS or SMS contributions.