Abstract
The off-diagonal hyperfine interaction between the and states in is evaluated in third-order MBPT giving and , respectively, for second-order energies of the and levels. This result is a factor of 10 smaller than one obtained from an uncorrelated first-order Dirac–Hartree–Fock calculation and used in the analysis of a recent high-precision measurement of the hyperfine structure [Gerginov et al. Phys. Rev. Lett. 91, 72301 (2003)]. The factor of 10 difference has negligible effect on the conclusions of the recent experiment but will become important for experiments carried out at a precision of better than .
- Received 21 April 2004
DOI:https://doi.org/10.1103/PhysRevA.70.014501
©2004 American Physical Society