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arXiv · 1206.5414

Eta-meson production in the resonance energy region

V. Shklyar·H. Lenske·U. Mosel
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Abstract

We perform an updated coupled-channel analysis of eta-meson production including all recent photoproduction data on the proton. The dip observed in the differential cross sections at c.m. energies W=1.68 GeV is explained by destructive interference between the $S_{11}(1535)$ and $S_{11}(1560)$ states. The effect from $P_{11}(1710)$ is found to be small but still important to reproduce the correct shape of the differential cross section. For the $\pi^- N \to \eta N$ scattering we suggest a reaction mechanism in terms of the $S_{11}(1535)$, $S_{11}(1560)$, and $P_{11}(1710)$ states. Our conclusion on the importance of the $S_{11}(1535)$, $S_{11}(1560)$, and $P_{11}(1710)$ resonances in the eta-production reactions is in line with our previous results. No strong indication for a narrow state with a width of 15 MeV and the mass of 1680 MeV is found in the analysis. $\eta N$ scattering length is extracted and discussed.

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V. Shklyar, H. Lenske, U. Mosel. 2012-06-23. Eta-meson production in the resonance energy region. https://doi.org/10.1103/physrevc.87.015201

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