Many-body aspects of the parameterization of the hyperfine and other atomic interactions

Abstract

The idea of the parametrization of atomic interactions, such as the hyperfine interaction, the spin-orbit interaction and the isotopic field shift, is reviewed from the point of view of atomic many-body theory. The close analogy between Goldstone perturbation diagrams and the angular-momentum diagrams of Jucys et al. is used extensively in the analysis. In the non-relativistic limit, when only electrostatic perturbations are considered, it is verified that the hyperfine interaction can be exactly described by the effective one-body operator, introduced by Harvey, providedLS-dependent parameters are used. When relativity is considered, it is shown that the consideration of effective one-body effects leads to the theory of Sandars and Beck, withLS-independent parameters, while the remaining effects can be represented byLS-dependent one-body operators of higher tensor ranks.