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The Linear Sigma Model at Work: Succesful Postdictions for Pion Scattering

J. L. Lucio·M. Napsuciale·M. Ruiz-Altaba
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Abstract

We enforce chiral Ward identities on the vertices of the linear sigma model to take into account the width of the scalar sigma, considered as a true physical resonance. We consider pion scattering at very low energies and, from a fit to the measured phase shifts in the various angular momentum and isospin channels, conclude a mass for the sigma of 600+200-100 MeV. Its width turns out to be of the same size.

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J. L. Lucio, M. Napsuciale, M. Ruiz-Altaba. 1999-03-20. The Linear Sigma Model at Work: Succesful Postdictions for Pion Scattering. https://arxiv.org/abs/hep-ph/9903420

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