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arXiv · 2512.22929

Low-energy $e^+\,e^-\to\gamma\,\gamma$ at NNLO in QED

Tim Engel·Marco Rocco·Adrian Signer·Yannick Ulrich
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Abstract

We present a fully differential computation of $e^+\,e^-\to\gamma\,\gamma$ at next-to-next-to-leading order in QED. The process has been implemented into McMule, completing its set of next-to-next-to-leading-order calculations for the most important $2 \to 2$ processes. The results allow for generic applications to electron-positron colliders with centre-of-mass energies up to a few GeV, particularly for luminosity measurements.

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Tim Engel, Marco Rocco, Adrian Signer, Yannick Ulrich. 2025-12-28. Low-energy $e^+\,e^-\to\gamma\,\gamma$ at NNLO in QED. https://arxiv.org/abs/2512.22929

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