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arXiv · 1706.01465

Extracting the sigma-term from low-energy pion-nucleon scattering

Jacobo Ruiz de Elvira·Martin Hoferichter·Bastian Kubis·Ulf-G. Meißner
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Abstract

We present an extraction of the pion-nucleon ($\pi N$) scattering lengths from low-energy $\pi N$ scattering, by fitting a representation based on Roy-Steiner equations to the low-energy data base. We show that the resulting values confirm the scattering-length determination from pionic atoms, and discuss the stability of the fit results regarding electromagnetic corrections and experimental normalization uncertainties in detail. Our results provide further evidence for a large $\pi N$ $\sigma$-term, $\sigma_{\pi N}=58(5)$ MeV, in agreement with, albeit less precise than, the determination from pionic atoms.

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Jacobo Ruiz de Elvira, Martin Hoferichter, Bastian Kubis, Ulf-G. Meißner. 2017-06-05. Extracting the sigma-term from low-energy pion-nucleon scattering. https://doi.org/10.1088/1361-6471/aa9422

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