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arXiv · 2202.01472

Lattice QCD calculation of the two-photon exchange contribution to the muonic-hydrogen Lamb shift

Yang Fu·Xu Feng·Lu-Chang Jin·Chen-Fei Lu
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Abstract

We develop a method for lattice QCD calculation of the two-photon exchange contribution to the muonic-hydrogen Lamb shift. To demonstrate its feasibility, we present the first lattice calculation with a gauge ensemble at $m_\pi = 142$ MeV. By adopting the infinite-volume reconstruction method along with an optimized subtraction scheme, we obtain $\Delta E_{\text{TPE}} = -28.9(4.9)~\mu\text{eV} + 93.72~\mu\text{eV}/\text{fm}^2 \cdot\langle r_p^2 \rangle$, or $\Delta E_{\text{TPE}} = 37.4(4.9)~\mu$eV, which is consistent with the previous theoretical results in a range of 20-50 $\mu$eV.

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Yang Fu, Xu Feng, Lu-Chang Jin, Chen-Fei Lu. 2022-02-03. Lattice QCD calculation of the two-photon exchange contribution to the muonic-hydrogen Lamb shift. https://doi.org/10.1103/physrevlett.128.172002

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