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arXiv · hep-ph/0508307

Gauge invariance in two-particle scattering

B. Borasoy·P. C. Bruns·U. -G. Meißner·R. Nißler
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Abstract

It is shown how gauge invariance is obtained for the coupling of a photon to a two-body state described by the solution of the Bethe-Salpeter equation. This is illustrated both for a complex scalar field theory and for interaction kernels derived from chiral effective Lagrangians.

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B. Borasoy, P. C. Bruns, U. -G. Meißner, R. Nißler. 2005-09-02. Gauge invariance in two-particle scattering. https://doi.org/10.1103/physrevc.72.065201

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