The Landé g-factors for the 1s22s22p1/2 and 1s22s22p3/2 states of middle-Z B-like ions: Importance from negative energy states

Abstract

In this work, we calculate the Landé g-factors for the $1s^{2}2s^2$ $2p_{1/2}$ and $1s^{2}2s^2$ $2p_{3/2}$ states in B-like systems with nuclear charges $Z$ ranging from 10 to 20. Our method starts with the Dirac–Coulomb–Breit Hamiltonian, incorporating electron correlation effects from both negative-energy and positive-energy states using third-order many-body perturbation theory, and including leading-order quantum electrodynamics (QED) corrections through an approximate method. A key aspect of this research is to elucidate the role played by negative-energy states in determining Landé g-factors for B-like ions. Our findings reveal that negative-energy states are crucial for accurately evaluating the Landé g-factors for these states. The contributions from negative-energy states and positive-energy states are of similar magnitude but with opposite signs, resulting in a significant cancellation. The accuracy of our calculations is verified by comparing our results with available experimental results, showing good agreement. This work may serve as a valuable reference for future precise calculations of Landé g-factors in heavy atomic systems.