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arXiv · 0910.0736

Isospin-breaking corrections to the pion-nucleon scattering lengths

Martin Hoferichter·Bastian Kubis·Ulf-G. Meißner
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Abstract

We analyze isospin breaking through quark mass differences and virtual photons in the pion-nucleon scattering lengths in all physical channels in the framework of covariant baryon chiral perturbation theory. The so-called triangle relation is found to be violated by about 1.5 %. We encounter a substantial isospin-breaking correction to neutral-pion-nucleon scattering beyond Weinberg's prediction due to a cusp effect. Finally, the application to hadronic atoms is briefly discussed.

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Martin Hoferichter, Bastian Kubis, Ulf-G. Meißner. 2009-10-05. Isospin-breaking corrections to the pion-nucleon scattering lengths. https://arxiv.org/abs/0910.0736

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