Relativistic nuclear recoil effects in hyperfine splitting of hydrogenic systems
Phys. Rev. A 113, 042813 – Published 14 April, 2026
DOI: https://doi.org/10.1103/t5cx-cjvd
Abstract
Finite nuclear mass corrections to the hyperfine splitting in hydrogenic systems are calculated using a combined relativistic heavy particle and nonrelativistic quantum electrodynamics. The obtained results are in disagreement with previous calculations by Bodwin and Yennie [Phys. Rev. D 37, 498 (1988)]. The comparison of improved theoretical predictions with the corresponding measurements in hydrogen reveals discrepancy, which may indicate problems with the proton structure corrections.