Determination of the scalar and vector polarizabilities of the cesium $6s{}^2{S}_{1/2}\to 7s{}^2{S}_{1/2}$ transition and implications for atomic parity non-conservation

Abstract

Using recent high-precision measurements of electric dipole matrix elements of atomic cesium, we make an improved determination of the scalar ($\alpha$) and vector ($\beta$) polarizabilities of the cesium $6s{}^2{S}_{1/2}\to 7s{}^2{S}_{1/2}$ transition calculated through a sum-over-states method. We report values of $\alpha =-268.82(30)a_0^3$ and $\beta =27.139(42)a_0^3$ with the highest precision to date. We find a discrepancy between our value of $\beta$ and the past preferred value, resulting in a significant shift in the value of the weak charge $Q_w$ of the cesium nucleus. Future work to resolve the differences in the polarizability will be critical for interpretation of parity non-conservation measurements in cesium, which have implications for physics beyond the Standard Model.

5 pages, 3 figures, 2 tables