Measurement of the Static Stark Shift of the 7s S21/2 Level in Atomic Cesium

We report a new precision measurement of the dc Stark shift of the 6s ²S1/2→7s ²S1/2 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 ~0.5%, or 4.7σ. We use this value to recalculate the magnitude of the reduced dipole matrix elements ⟨7s||r||7pⱼ⟩, as well as the vector transition polarizability for the 6s→7s transition, β=27.043 (36) a₀³. This determination helps resolve a critical discrepancy between two techniques for determining the vector polarizability.