QED corrections of orders and for spin-independent rovibrational transitions beyond Born-Oppenheimer approximation
Phys. Rev. A 114, 032814 – Published 10 September, 2026
DOI: https://doi.org/10.1103/x5q9-pdcj
Abstract
The effective Hamiltonian of - and -order corrections for hydrogen molecular ions has been derived by Zhong et al. [Z.-X. Zhong, W.-P. Zhou, and X.-S. Mei, Phys. Rev. A 98, 032502 (2018)]; in this work we express the energy correction in the form of finite-value effective operators. The cutoff regularization scheme is used to determine the finite part of divergent operators of the leading-order recoil corrections. Numerical calculations of first-order contributions are performed in the Hylleraas basis set. Combining the second-order terms calculated in recent work [V. I. Korobov, J.-P. Karr, and Z.-X. Zhong, Mol. Phys. e2563023 (2025)], the -order corrections for the fundamental rovibrational transition are obtained with an uncertainty three times smaller than in previous calculations.