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arXiv · 1211.1485

Improved dispersive analysis of the scalar form factor of the nucleon

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

We present a coupled system of integral equations for the pi pi --> Nbar N and Kbar K --> Nbar N S-waves derived from Roy-Steiner equations for pion-nucleon scattering. We discuss the solution of the corresponding two-channel Muskhelishvili-Omnes problem and apply the results to a dispersive analysis of the scalar form factor of the nucleon fully including Kbar K intermediate states. In particular, we determine the corrections Delta_sigma and Delta_D, which are needed for the extraction of the pion-nucleon sigma term from pi N scattering, and show that the difference Delta_D - Delta_sigma=(-1.8 +/- 0.2) MeV is insensitive to the input pi N parameters.

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Martin Hoferichter, Christoph Ditsche, Bastian Kubis, Ulf-G. Meißner. 2012-11-07. Improved dispersive analysis of the scalar form factor of the nucleon. https://arxiv.org/abs/1211.1485

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