Precision Test of Many-Body QED in the Be${}^{+}$ $2p$ Fine Structure Doublet Using Short-Lived Isotopes

Abstract

Absolute transition frequencies of the $2s{}^2{\mathrm{S}}_{1/2}\to 2p{}^2{\mathrm{P}}_{1/2,3/2}$ transitions in Be${}^{+}$ were measured for the isotopes ${}^{7,9-12}$Be. The fine structure splitting of the $2p$ state and its isotope dependence are extracted and compared to results of \textit{ab initio} calculations using explicitly correlated basis functions, including relativistic and quantum electrodynamics effects at the order of $m{\alpha }^6$ and $m{\alpha }^7\ln \alpha$. Accuracy has been improved in both the theory and experiment by 2 orders of magnitude, and good agreement is observed. This represents one of the most accurate tests of quantum electrodynamics for many-electron systems, being insensitive to nuclear uncertainties.

5 pages, 2 figures

References in corpus (7)

• Nuclear Charge Radii of Be-7,9,10 and the one-neutron halo nucleus Be-11
• g factor of lithiumlike silicon 28Si11+
• Test of Time Dilation Using Stored Li+ Ions as Clocks at Relativistic Speed
• Many-electron QED corrections to the g factor of lithiumlike ions
• Fine and hyperfine splitting of the 2P state in Li and Be${}^{+}$
• Quantum electrodynamics corrections to the $2P$ fine splitting in Li
• Quantum electrodynamics $m{\alpha }^6$ and $m{\alpha }^7\ln \alpha$ corrections to the fine splitting in Li and Be${}^{+}$

Cited by in corpus (4)

• Unexpectedly large difference of the electron density at the nucleus in the 4p ${}^2$P${}_{1/2,3/2}$ fine-structure doublet of Ca${}^{+}$
• Frequency-comb based collinear laser spectroscopy of Be for nuclear structure investigations and many-body QED tests
• Fine and hyperfine splitting of the low-lying states of ${}^9$Be
• Detecting weak beryllium lines with CUBES