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arXiv · hep-ph/9510302

The two-fermion vector potential of constraint theory from Feynman diagrams

H. Jallouli·H. Sazdjian
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Abstract

The relativistic fermion-antifermion bound state vector potential of constraint theory is calculated, in perturbation theory, by means of the Lippmann-Schwinger type equation that relates it to the scattering amplitude. Leading contributions of n-photon exchange diagrams are calculated in an approximation scheme that adapts eikonal approximation to the bound state problem. They produce terms proportional, in three-dimensional x-space, to $(α/r)^n$. The series of leading contributions is summed.

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H. Jallouli, H. Sazdjian. 1995-10-16. The two-fermion vector potential of constraint theory from Feynman diagrams. https://doi.org/10.1016/0370-2693(95)01388-1

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