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arXiv · hep-ph/9304275

Chiral Corrections to the S-Wave Pion-Nucleon Scattering Lengths

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

We calculate the chiral corrections to Weinberg's prediction for the S--wave $πN$ scattering lengths up--to--and--including order ${\cal O}(M_π^3)$ making use of heavy baryon chiral perturbation theory. For the isospin--odd scattering length $a^-$ these corrections are small and bring the prediction closer to the empirical value. In the case of the isospin--even $a^+$ large cancellations appear so that the ${\cal O}(M_π^3)$ result depends sensitively on certain resonance parameters which enter the calculation of the contact terms present at next--to--leading order.

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V. Bernard, N. Kaiser, Ulf-G. Meißner. 1993-04-20. Chiral Corrections to the S-Wave Pion-Nucleon Scattering Lengths. https://doi.org/10.1016/0370-2693(93)90956-i

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