Dynamical polarizability of atoms in arbitrary light fields: general   theory and application to cesium
  We present a systematic derivation of the dynamical polarizability and the ac Stark shift of the ground and excited states of atoms interacting with a far-off-resonance light field of arbitrary polarization. We calculate the scalar, vector, and tensor polarizabilities of atomic cesium using resonance wavelengths and reduced matrix elements for a large number of transitions. We analyze the properties of the fictitious magnetic field produced by the vector polarizability in conjunction with the ellipticity of the polarization of the light field. 
Fam Le Kien and Philipp Schneeweiss and Arno Rauschenbeutel
physics.atom-ph quant-ph