Abstract
We present a new theoretical analysis of the strongly suppressed F- and M-dependent Stark shifts of the Cs ground-state hyperfine structure. Our treatment uses third-order perturbation theory including off-diagonal hyperfine interactions not considered in earlier treatments. A numerical evaluation of the perturbation sum using bound states up to n = 200 yields ground-state tensor polarizabilities α2(6S1/2,F) which are in good agreement with experimental values, thereby bridging the 40-year-old gap between experiments and theory. We have further found that the tensor polarizabilities of the two ground-state hyperfine manifolds have opposite signs, in disagreement with an earlier derivation. This sign error has a direct implication for the precise evaluation of the blackbody radiation shift in primary frequency standards.