Magnetic-dipole transitions in highly charged Co-like ions to study the QED and higher order effects in EBITs

Atomic theory is complicated for many-body systems where proper treatment of the correlation effects can be challenging. As correlation decreases rapidly with Z, highly charged ions offer test grounds to benchmark modern atomic theories. These ions also have enhanced relativistic and quantum electrodynamics (QED) effects and can be easily created with Electron Beam Ion Traps (EBIT). Recently highly accurate tests of Breit and QED effects on systems with suppressed correlations and enhanced relativistic effects, labeled as “Layzer-quenched” systems [1] have been proposed and studied [2,3]. We present direct measurements of the 3d^{9 2}D_3/2 → ²D_5/2 fine structure of Co-like Yb, Re, Os, and Ir with the National Institute of Standards and Technology EBIT facility. Comparisons with the existing theories [4-5] are made in an effort to understand the Breit interaction and the self-energy contribution to QED effects.



[1] D. Layzer, Annals of Physics 8, 271 (1959).

[2] R. Si, X. L. Guo, T. Brage, C. Y. Chen, R. Hutton, and C. F. Fischer, Physical Review A 98, 012504 (R) (2018).

[3] G. O’Neil et al, Physical Review A 102, 032803 (2020).

[4] T. A. Welton, Physical Review 74, 1157 (1948).

[5] V. Shabaev, I. Tupitsyn, and V. Yerokhin, Computational Physics Communications 189, 175 (2015).