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arXiv · hep-ph/9506204

Chiral Prediction for the $πN$ Scattering Length $a^-$ to Order ${\cal O}(M_π^4)$

V. Bernard·N. Kaiser·Ulf-G. Meißner
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Abstract

We evaluate the S-wave pion--nucleon scattering length $a^-$ in the framework of heavy baryon chiral perturbation theory up--to--and--including terms of order $M_π^4$. We show that the order $M_π^4$ piece of the isovector amplitude at threshold, $T^-_{\rm thr}$, vanishes exactly. We predict for the isovector scattering length, $0.088 \, M_{π^+}^{-1} \le a^- \le 0.096 \, M_{π^+}^{-1}$.

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V. Bernard, N. Kaiser, Ulf-G. Meißner. 1995-06-01. Chiral Prediction for the $πN$ Scattering Length $a^-$ to Order ${\cal O}(M_π^4)$. https://doi.org/10.1103/physrevc.52.2185

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