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Unitarity Constraints on effective interaction in $πN$ scattering

Mingxing Luo·Yong Wang·Guohuai Zhu
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Abstract

Positivity constraints are derived on pion-nucleon scattering amplitudes and their even-order derivatives inside the Mandelstam Triangle with the help of dispersion relations. Fairly interesting constraints are obtained on some of the low energy constants, by a combination of the chiral perturbation theory for heavy baryons and existing fitting results from available pion-nucleon phase shifts at intermediate energies.

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Mingxing Luo, Yong Wang, Guohuai Zhu. 2007-05-17. Unitarity Constraints on effective interaction in $πN$ scattering. https://doi.org/10.1016/j.physletb.2007.03.052

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