Determination of the scalar and vector polarizabilities of the cesium $6s \ ^2S_{1/2} \rightarrow 7s \ ^2S_{1/2}$ 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 ($α$) and vector ($β$) polarizabilities of the cesium $6s \ ^2S_{1/2} \rightarrow 7s \ ^2S_{1/2} $ transition calculated through a sum-over-states method. We report values of $α= -268.82 \ (30) \ a_0^3$ and $β= 27.139 \ (42) \ a_0^3$ with the highest precision to date. We find a discrepancy between our value of $β$ 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.