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arXiv · 1611.03773

Bound state structure and electromagnetic form factor beyond the ladder approximation

V. Gigante·J. H. Alvarenga Nogueira·E. Ydrefors·C. Gutierrez·V. A. Karmanov·T. Frederico
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Abstract

We investigate the response of the bound state structure of a two-boson system, within a Yukawa model with a scalar boson exchange, to the inclusion of the cross-ladder contribution to the ladder kernel of the Bethe-Salpeter equation. The equation is solved by means of the Nakanishi integral representation and light-front projection. The valence light-front wave function and the elastic electromagnetic form factor beyond the impulse approximation, with the inclusion of the two-body current, generated by the cross-ladder kernel, are computed. The valence wave function and electromagnetic form factor, considering both ladder and ladder plus cross-ladder kernels, are studied in detail. Their asymptotic forms are found to be quite independent of the inclusion of the cross-ladder kernel, for a given binding energy. The asymptotic decrease of form factor agrees with the counting rules. This analysis can be generalized to fermionic systems, with a wide application in the study of the meson structure.

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V. Gigante, J. H. Alvarenga Nogueira, E. Ydrefors, C. Gutierrez, V. A. Karmanov, T. Frederico. 2016-11-11. Bound state structure and electromagnetic form factor beyond the ladder approximation. https://doi.org/10.1103/physrevd.95.056012

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