Hyperfine structure and g factor in heavy ions: test of QED in strong fields

• Applicant: Privatdozent Dr. Andrey V. Volotka
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2010 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 169785323

The current project is devoted to developments of the ab initio quantum-electrodynamical (QED) approach for the evaluation of the hyperfine splitting and the bound-electron g factor of Li- and B-like ions. In the first phase of this project the contributions of the most difficult many-electron QED Feynman diagrams - the screened radiative and two-photon exchange corrections - were rigorously evaluated for Li-like ions. In the second phase the theoretical accuracy of the g factor of Li-like ions was further substantially increased, and, moreover, the nuclear-polarization and screened nuclear polarization corrections were evaluated for H-, Li-, and B-like ions. It was shown, that the nuclear polarization contributions can be substantially canceled simultaneously with the rigid nuclear corrections. This allows for new prospects for probing the QED effects in strong electromagnetic field and the determination of fundamental constants.Within the next stage we plan to improve further the theoretical accuracy of the g factor of Li-ike ions and to extend the rigorous calculations of the two-photon exchange and screened QED diagrams to the hyperfine splitting and the g factor of B-like ions. As a result, these investigations will widen the theoretical basis for the stringent tests of the magnetic sector of bound-state QED at strongest electromagnetic field.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Stephan Fritzsche