Laser-resonance Lamb-shift measurement in hydrogenlike phosphorus

Abstract

We report our final result on the Lamb-shift measurement in hydrogenlike phosphorous using the $2s_{\frac{1}{2}}-2\mathrm{}{p}_{\frac{3}{2}}$ laser-resonance method. From the measured value of the $2s_{\frac{1}{2}}-2\mathrm{}{p}_{\frac{3}{2}}$ energy splitting [539.60(20) THz, or 5555.8(2.0) Å] the Lamb shift $S$ is deduced in the framework of Erickson's and Mohr's calculations. $S_{\mathrm{expt}}^{\mathrm{E}}$ and $S_{\mathrm{expt}}^{\mathrm{M}}$ are the results of the subtraction of the measured $2s_{\frac{1}{2}}-2\mathrm{}{p}_{\frac{3}{2}}$ energy splitting and the fine structure calculated by the two authors, respectively. The results, $|S_{\mathrm{E}}-S_{\mathrm{expt}}^{\mathrm{E}}|=0.43\mathrm{}\pm 0.20$ THz and $|S_{\mathrm{M}}-S_{\mathrm{expt}}^{\mathrm{M}}|=0.12\mathrm{}\pm 0.20$ THz, indicate agreement with Mohr's theoretical approach ($S_{\mathrm{M}}$) and are more than two standard deviations from Erickson's calculations ($S_{\mathrm{E}}$). A general overview on the experimental techniques and results is given. The general trend of the presently available experimental results on Lamb-shift measurements are compared with Mohr's calculations.