This book presents several precision measurements performed on atomic cesium and related to ongoing efforts toward a new measurement of the Weinberg mixing angle QW at low momentum transfer. The ultimate goal of this research program is an improved measurement of the extremely weak electric-dipole transition moment Epv of the 6s 2S1/2 ? 7s 2S1/2 transition of cesium, which is strictly electric-dipole forbidden without the weak force. Due to state mixing by the weak interaction, however, the optical transition is allowed, albeit very weakly, 10-11ea0. The magnitude of Epv yields the weak mixing angle QW and improving the precision of QW provides a direct test of the standard model of particle physics. The three specific measurements described in this thesis are: hyperfine coupling constants of several states; the static Stark polarizability of the 7s 2S1/2 state; and the ratio of the scalar to vector transition polarizabilities for the 6s ? 7s transition. In addition, it describes a new optical phase locking technique developed by the author to allow interference measurements on any of the hyperfine components of the 6s ? 7s transition. This technique is instrumental in a future measurement of Epv /ß.
