Specific mass shift of the (4s4p) 1 ,3P states in calcium studied with many-body perturbation theory

摘要: Many-body perturbation theory was applied to calculate the specific mass shift of (4s4p) $^{1}$,3P states in Ca relative 4s ground state ${\mathrm{Ca}}^{+}$. The interaction between each valence electron and core treated same way as level isotope shifts alkali metals earlier work. strong correlation two electrons neutral self-consistently by iterative solution pair equation describing their its effect on evaluated for helium. However, also is important. All second-order a large number third- (and higher-) order diagrams this type were included, but certain important third-order could not yet be evaluated. Our final results, -31 -1533 MHz, respectively, 4 $^{1}P$ $^{3}P$ $^{48}\mathrm{Ca}$ $^{40}\mathrm{Ca}$, show only qualitative agreement with experimental values, -120(9) -1116(8) MHz. This surprising, view many competing effects contributions larger than value. remaining discrepancies are consistent expected size neglected illustrate importance core-valence correlation.