A many-body calculation of the hyperfine interaction in the lowest2 S and2 P states of li-like systems

A non-relativistic perturbation method of Brueckner-Goldstone type is used to calculate the hyperfine interactions in the lowest² S and² P states of the Li-like systems, Li, Be⁺, B²⁺, C³⁺, N⁴⁺, O⁵⁺ and F⁶⁺. The effect of the polarization of the closed shell is treated to all orders of perturbation, while the correlation effect is calculated in the lowest order, i.e. in the third order of the perturbation expansion. Experimental data are at present available only for Li, Be⁺ and F⁶⁺, and the agreement with the calculated values is in these cases very good, usually within the experimental uncertainties. This implies that the predictions made in the remaining cases should be quite reliable, which may simplify the experimental determination of these quantities. Theoretical values are also given for the quadrupole interaction, which can be used to determine the nuclear quadrupole moments, when accurate experimental information becomes available.