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eta-Nucleon Scattering Length and Effective Range uncertainties

A. M. Green·S. Wycech
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Abstract

The coupled eta-N, pi-N, gamma-N, 2pi-N system is described by a K-matrix method. The parameters in this model are adjusted to get an optimal fit to pi-N-->pi-N, pi-N-->eta-N, gamma-N-->pi-N and gamma-N-->eta-N data in an energy range of about 100 MeV or so each side of the eta-threshold. Compared with our earlier analysis, we now utilize recent Crystal Ball data. However, the outcome confirms our previous result that the eta-nucleon scattering length (a) is large with a value of 0.91(6)+i0.27(2) fm.

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A. M. Green, S. Wycech. 2005-06-28. eta-Nucleon Scattering Length and Effective Range uncertainties. https://doi.org/10.1103/physrevc.71.014001%2010.1103%2Fphysrevc.72.029902

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