RESUMEN
We report a new precision measurement of the dc Stark shift of the 6s ^{2}S_{1/2}â7s ^{2}S_{1/2} transition in atomic cesium-133. Our result is 0.72246 (29) Hz(V/cm)^{-2}. This result differs from a previous measurement of the Stark shift by â¼0.5%, or 4.7σ. We use this value to recalculate the magnitude of the reduced dipole matrix elements ⟨7s||r||7p_{j}⟩, as well as the vector transition polarizability for the 6sâ7s transition, ß[over Ë]=27.043 (36) a_{0}^{3}. This determination helps resolve a critical discrepancy between two techniques for determining the vector polarizability.
RESUMEN
Using recent high-precision measurements of electric dipole matrix elements of atomic cesium, we make an improved determination of the scalar (α) and vector (ß) polarizabilities of the cesium 6s^{2}S_{1/2}â7s^{2}S_{1/2} transition calculated through a sum-over-states method. We report values of α=-268.82(30)a_{0}^{3} and ß=27.139(42)a_{0}^{3} with the highest precision to date. We find a discrepancy between our value of ß 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 nonconservation measurements in cesium, which have implications for physics beyond the standard model.