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Order m alpha^8 Contributions to the Decay Rate of Orthopositronium

P. Labelle·G. P. Lepage·U. Magnea
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Abstract

We discuss how contributions to the order ${\cal O} (m α^8)$ orthopositronium decay rate can be separated into two categories, one due to relativistic momenta and calculable in terms of QED scattering amplitudes, the other due to low momenta and calculable in the simpler framework of a low-energy effective theory (NRQED). We report new results for all low-momentum contributions, and give a formula relating the remaining contributions to conventional (on-shell) QED scattering amplitudes.

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P. Labelle, G. P. Lepage, U. Magnea. 1993-10-01. Order m alpha^8 Contributions to the Decay Rate of Orthopositronium. https://doi.org/10.1103/physrevlett.72.2006

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