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

Wilfried Nörtershäuser, Christopher Geppert, Andreas Krieger +13

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 st…