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arXiv · 1610.02921

Systematic effects in the low-energy behavior of the current SAID solution for the pion-nucleon system

Evangelos Matsinos·Guenther Rasche
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Abstract

We investigate the description of the pion-nucleon experimental data at low energy (i.e., below pion laboratory kinetic energy of $100$ MeV) on the basis of the current SAID solution (WI08). We demonstrate that, in a self-consistent analysis scheme, the scale factors of the fits based on the Arndt-Roper formula come out independent of the beam energy and `cluster' around the expectation value of $1$. We report systematic effects in the low-energy behavior of the WI08 solution. These effects indicate that at least one of the three following assumptions, underlying the WI08 analysis, does \emph{not} hold, namely that: a) the bulk of the data is reliable, b) the electromagnetic effects are correctly accounted for, and c) the isospin invariance in the strong interactions of the $πN$ system is valid.

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Evangelos Matsinos, Guenther Rasche. 2017-03-10. Systematic effects in the low-energy behavior of the current SAID solution for the pion-nucleon system. https://doi.org/10.1142/s0218301317500021

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