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arXiv · 2111.04668

$\pi-\pi$ scattering, QED and finite-volume quantization

Norman Christ·Xu Feng·Joseph Karpie·Tuan Nguyen
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Abstract

Using the Coulomb gauge formulation of QED we present a lattice QCD procedure to calculate the $\pi^+\pi^+$ scattering phase shift including the effects of the Coulomb potential which appears in this formulation. The approach described here incorporates the effects of relativity and avoids finite-volume corrections that vanish as a power of the volume in which the lattice calculation is performed. This is the first step in developing a complete lattice QCD calculation of the electromagnetic and isospin-breaking light-quark mass contributions to $\varepsilon'$, the parameter describing direct CP violating effects in $K_L\to\pi\pi$ decay.

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Norman Christ, Xu Feng, Joseph Karpie, Tuan Nguyen. 2021-11-08. $\pi-\pi$ scattering, QED and finite-volume quantization. https://doi.org/10.1103/physrevd.106.014508

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