Polarizability measurements of the8s2S1/2and9s

Abstract

We report hyperfine-resolved scalar polarizabilities for cesium's 8s 2 S 1/2 and 9s 2 S 1/2 states using resonant two-photon spectroscopy in both an effusive beam and a vapor cell. Electric-field strengths are measured in situ, and the frequency scale is directly referenced to the ground-state hyperfine splitting of atomic rubidium. The measured 8s 2 S 1/2 scalar polarizability is 38 370 ± 380a 3 0 , which agrees well with previously reported theoretical and experimental values. The measured 9s 2 S 1/2 scalar polarizability is 150 700 ± 1500a 3 0 , which agrees within 2σ with the theory, but we are unaware of previous measurements. We verify that the 8s 2 S 1/2 state polarizability is independent of the hyperfine level, placing an upper limit of 200 ± 260a 3 0 on the differential polarizability-this agrees with previous observations. We also measure a null differential polarizability between the hyperfine levels for the 9s 2 S 1/2 of 490 ± 450a 3 0 .