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arXiv · 2002.02351

How does the $S_{11}$ $N^*(890)$ state emerge from a naive $K$ matrix fit?

Yao Ma·Wen-Qi Niu·Yu-Fei Wang·Han-Qing Zheng
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Abstract

We give a pedagogical analysis on $K$ matrix models describing the $\pi N$ scattering amplitude, in $S_{11}$ channel at low energies. We show how the correct use of analyticity in the $s$ channel and crossing symmetry in $t$ and $u$ channels leads to a much improved analytic behavior in the negative $s$ region, in agreement with the prediction from chiral perturbation amplitudes in its validity region. The analysis leads again to the conclusion that a genuine $N^*(890)$ resonance exists.

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Yao Ma, Wen-Qi Niu, Yu-Fei Wang, Han-Qing Zheng. 2020-02-06. How does the $S_{11}$ $N^*(890)$ state emerge from a naive $K$ matrix fit?. https://doi.org/10.1088/1572-9494%2Faba25d

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