The influence of hypothetical new interactions beyond the standard model on atomic spectra has attracted recent interest. In the present work, interelectronic photon-exchange corrections and radiative quantum electrodynamic corrections to the hypothetical contribution to the energy levels of few-electron ions from a new interaction are calculated. The ground states of H-like, Li-like, and B-like ions are considered, as motivated by proposals to use isotope shift spectroscopy of few-electron ions in order to set stringent constraints on hypothetical new interactions. It is shown that, for light Li-like and B-like ions, photon-exchange corrections are comparable to or even larger than, by up to several orders of magnitude, the leading one-electron contribution from the new interaction, when the latter is mediated by heavy bosons.

• Received 31 May 2021
• Revised 4 August 2021
• Accepted 1 September 2021

DOI:https://doi.org/10.1103/PhysRevA.104.032825

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.

Published by the American Physical Society