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arXiv · 2012.00503

Radiative $\bm{α^7m}$ QED contribution to the helium Lamb shift

Vojtěch Patkóš·Vladimir A. Yerokhin·Krzysztof Pachucki
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Abstract

We present a derivation of the last unknown part of the $α^7m$ contribution to the Lamb shift of a two-electron atom, induced by the radiative QED effects beyond the Bethe logarithm. This derivation is performed in the framework of nonrelativistic quantum electrodynamics and is valid for the triplet (spin $S = 1$) atomic states. The obtained formulas are free from any divergences and are suitable for a numerical evaluation. This opens a way for a complete numerical calculation of the $α^7m$ QED effects in helium, which will allow an accurate determination of the nuclear charge radius from measurements of helium transition frequencies.

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Vojtěch Patkóš, Vladimir A. Yerokhin, Krzysztof Pachucki. 2021-01-06. Radiative $\bm{α^7m}$ QED contribution to the helium Lamb shift. https://doi.org/10.1103/physreva.103.012803

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