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arXiv · nucl-th/9908045

The quark-photon vertex and meson electromagnetic form factors

P. Maris·P. C. Tandy
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Abstract

The ladder Bethe-Salpeter solution for the dressed photon-quark vertex is used to study the low-momentum behavior of the pion electromagnetic and the $γ^\star π^0 γ$ transition form factors. With model parameters previously fixed by light meson masses and decay constants, the low-momentum slope of both form factors is in excellent agreement with the data. In comparison, the often-used Ball-Chiu Ansatz for the vertex is found to be deficient; less than half of the obtained $r_π^2$ is generated by that Ansatz while the remainder of the charge radius could be attributed to the tail of the $ρ$ resonance.

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P. Maris, P. C. Tandy. 1999-08-12. The quark-photon vertex and meson electromagnetic form factors. https://doi.org/10.1016/s0375-9474(99)00627-2

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