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arXiv · hep-ph/0212256

Eta, eta-prime photoproduction and electroproduction off nucleons

B. Borasoy·E. Marco·S. Wetzel
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Abstract

The photo- and electroproduction of eta, eta-prime mesons on nucleons are investigated within a relativistic chiral unitary approach based on coupled channels. The s-wave potentials for electroproduction and meson-baryon scattering are derived from a chiral effective Lagrangian which includes the eta-prime as an explicit degree of freedom and incorporates important features of the underlying QCD Lagrangian such as the axial U(1) anomaly. The effective potentials are iterated in a Bethe-Salpeter equation and cross sections for eta, eta-prime photo- and electroproduction from nucleons are obtained. The results for the eta-prime photoproduction cross section on protons reproduce the appearance of an S_{11} resonance around 1.9 GeV observed at ELSA. The inclusion of electromagnetic form factors increases the predicted eta electroproduction cross sections on the proton, providing a qualitative explanation for the hard form factor of the photocoupling amplitude observed at CLAS.

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B. Borasoy, E. Marco, S. Wetzel. 2002-12-17. Eta, eta-prime photoproduction and electroproduction off nucleons. https://doi.org/10.1103/physrevc.66.055208

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