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Pion-Lambda-Sigma Coupling Extracted from Hyperonic Atoms

B. Loiseau·S. Wycech
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Abstract

The latest measurements of the atomic level width in Sigma-hyperonic Pb atom offer the most accurate datum in the region of low-energy Sigma-hyperon physics. Atomic widths are due to the conversion of Sigma-nucleon into Lambda-nucleon. In high angular momentum states this conversion is dominated by the one-pion exchange. A joint analysis of the data of the scattering of negative-Sigma on proton converting into a Lambda and a neutron and of the atomic widths allows to extract a pseudovector pion-hyperon-Sigma coupling constant of 0.048 with a statistical error of +-0.005 and a systematic one of +-0.004. This corresponds to a pseudoscalar coupling constant of 13.3 with a statistical uncertainty of 1.4 and a systematic one of 1.1.

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B. Loiseau, S. Wycech. 2000-12-01. Pion-Lambda-Sigma Coupling Extracted from Hyperonic Atoms. https://doi.org/10.1103/physrevc.63.034003

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