Speaker
Description
The g-factor of bound electrons can be measured and calculated with high
accuracy. Comparisons between the theoretical and experimental values of the
g-factor allow precision tests of QED in the presence of strong electric
background fields and the determination of fundamental constants.
We present the status of our ongoing calculations of the two-loop self-energy
correction to the g-factor of the bound electron in hydrogenlike ions. This
correction currently gives rise to the largest uncertainty of theoretical
g-factor predictions. The interaction with the nuclear potential is taken into
account non-perturbatively in our calculations, in order to achieve a high
accuracy for the bound electron in heavy ions. We have obtained full results
for the loop-after-loop diagrams, and partial results for the nested and
overlapping loop diagrams. In the latter case, we treat the Coulomb
interaction in intermediate states to zero and first order [1].
Our results will be highly relevant for planned g-factor measurements with
high-Z ions in the near future as well as for an independent determination of
the fine-structure constant from the bound-electron g-factor.
[1] B. Sikora, V. A. Yerokhin, N. S. Oreshkina et al., arXiv:1804.05733v1
[physics.atom-ph] (2018).
