GJFactor of the LowestP11andP13States of Ba; Level-Crossing Determination ofA(P11)μ0gJ(P11)ofHg199

Abstract

The ${g}_{J}(^{3}P_{1})$ and ${g}_{J}(^{1}P_{1})$ factors of the ($6s6p$) configuration in barium have been determined in a double-resonance experiment. The ratio $\frac{A(^{1}P_{1})}{[{\ensuremath{\mu}}_{0}{g}_{J}(^{1}P_{1})]}$ of the ($6s6p$) configuration in ${\mathrm{Hg}}^{199}$ has been measured in a level-crossing experiment. The results are: ${g}_{J}(^{1}P_{1}, \mathrm{Ba})=1.0039\ifmmode\pm\else\textpm\fi{}0.0008$, ${g}_{J}(^{3}P_{1}, \mathrm{Ba})=1.4973\ifmmode\pm\else\textpm\fi{}0.0007$, $\ensuremath{-}\frac{hA(^{1}P_{1}, {\mathrm{Hg}}^{199})}{[{\ensuremath{\mu}}_{0}{g}_{J}(^{1}P_{1}, {\mathrm{Hg}}^{199})]}=2523.0\ifmmode\pm\else\textpm\fi{}3.0$ G. From the values of $A(^{1}P_{1}, {\mathrm{Hg}}^{199})$ obtained from optical spectroscopy, a value of ${g}_{J}(^{1}P_{1}, \mathrm{Hg})$ is derived: ${g}_{J}(^{1}P_{1}, \mathrm{Hg})=1.0127\ifmmode\pm\else\textpm\fi{}0.0050$. We have summarized all lifetime and ${g}_{J}$ values for the first excited $\mathrm{sp}$ configuration of the group-II elements. With these results, a comparison of the three different methods of calculating the intermediate coupling coefficients is presented and all methods are found to be in excellent agreement. Previous level-crossing results for the lifetime and hfs of ${\mathrm{Ba}}^{137}$ have been corrected using the presently determined value of ${g}_{J}(^{1}P_{1})$. These corrected results are in much better agreement with other experiments.