2024/11/02 by A. V. Malyshev, Y. S. Kozhedub, Malyshev, A. V. +5 · 1 citation
Engineering · Physics and Astronomy · #Atomic Physics (physics.atom-ph) #Atomic and Molecular Physics #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Laser-induced spectroscopy and plasma
paper · pdf · doi:10.48550/arxiv.2411.01241
openalex publication_date 2024/11/02 · openalex created_date 2024/11/14 · openalex updated_date 2026/07/28
The ab initio approach is used to evaluate the excitation energies of the 2s2p 2S+1PJ states from the ground state as well as the 2s2p 3P1 → 2s2p 3P0 and 2s2p 3P2 → 2s2p 3P1 transition energies for selected Be-like highly-charged ions over a wide range: from \rm Ar14+ to \rm U88+. The issue of a strong level mixing due to the proximity of states with the same symmetry is addressed by applying the QED perturbation theory for quasidegenerate levels. The employed approach combines a rigorous perturbative QED treatment up to the second order with electron-electron correlation contributions of the third and higher orders calculated in the Breit approximation. The higher-order QED effects are estimated using the model-QED-operator approach. The nuclear-recoil and nuclear-polarization effects are taken into account as well. The performed calculations are accompanied with a thorough analysis of uncertainties due to uncalculated effects. The most accurate theoretical predictions for the excitation and transition energies in Be-like ions are obtained, which, in general, are in perfect agreement with the available experimental data.