QED calculations of the excited-state g-factor in high-Z boron-like ions

Introduction

Recent decades have seen steady interest in the determination of the electronic g-factor of highly charged ions. Comparison of theoretical calculations and experimental measurements provides precise tests of bound-state QED and has already led to the most accurate determination of the electron mass value. High-Z ions provide unique conditions with the strongest electromagnetic fields for electrons, which makes them extremely sensitive to possible variations in fine structure constant and manifestations of dark matter.

This study is devoted to theoretical calculations of the electronic g-factor of boron-like high-Z ions in the 2p3/2 excited state. Consideration of B-like ions, on the one hand, allows us to perform theoretical calculations accurately enough. On the other hand, it is more suitable for experimental studies, due to the complexity of ion production with the innermost shell ionization. From an experimental point of view, it is also important to describe not only the 2p1/2 ground state, but also the 2p3/2 excited state, since they can both be measured in a single setup.

Methods

The total g-factor value includes corrections for the finite nuclear size and nuclear recoil effects, screened QED, and interelectronic interaction. The one-photon exchange and one-loop radiative corrections are evaluated rigorously within the QED formalism. The electron-correlation contributions of the second and higher orders are accounted for within the Breit approximation. Two-loop and higher orders of QED corrections have been estimated employing the non-relativistic estimation.

Results and Discussion

We presented total g-factor values for several high-Z boron-like ions in the 2p3/2 state. Contributions of interelectronic interaction and one-loop QED are presented for different screened potentials. The accuracy of the total values is limited by the two-loop QED contributions.

Conclusions

Obtained results in comparison with experimental data may be applied for determination of fundamental constants, bound-state QED tests, or the search for New Physics.