Ab initiocalculations of off-diagonal hyperfine interaction in cesium

Abstract

We have performed a relativistic many-body calculation of the off-diagonal hyperfine interaction mixing amplitude ${M}_{\mathrm{hf}}$ for the $6s\ensuremath{-}7s$ transition in atomic cesium. The ab initio result ${M}_{\mathrm{hf}}=0.8070(73)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}|{\ensuremath{\mu}}_{\mathrm{B}}/c|$ is in excellent agreement with a previous semiempirical value ${M}_{\mathrm{hf}}=0.8094(20)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}|{\ensuremath{\mu}}_{\mathrm{B}}/c|.$