Precision lifetimes for the ${\mathrm{Ca}}^{+}$ 4p ${}_{}{}^2{}_{}{}^{}$P levels: Experiment challenges theory at the 1% level

The mean lifetimes τ of the ${\mathrm{Ca}}^{+}$ 4p ${}_{}{}^2{}_{}{}^{}$${\mathit{P}}_{3/2}$ and ${}_{}{}^2{}_{}{}^{}$${\mathit{P}}_{1/2}$ levels have been measured to ≊0.3% precision using a variant of the collinear laser-beam–ion-beam spectroscopy technique. Like previously measured precision lifetimes of light alkali-metal-like systems, these data fall significantly higher than calculations by the most recent multiconfiguration Hartree-Fock and relativistic many-body perturbation theories. Discrepancies between experiment and theory for alkali-metal-like systems have implications for the interpretation of parity-violation research.