Remarks on the pion–nucleon σ -term

Hoferichter, Martin (Institute for Nuclear Theory, University of Washington, Seattle, WA, 98195-1550, USA) ; Ruiz de Elvira, Jacobo (Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Bethe Center for Theoretical Physics, Universität Bonn, Bonn, D-53115, Germany) ; Kubis, Bastian (Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Bethe Center for Theoretical Physics, Universität Bonn, Bonn, D-53115, Germany) ; Meißner, Ulf-G. (Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Bethe Center for Theoretical Physics, Universität Bonn, Bonn, D-53115, Germany) (Institut für Kernphysik, Institute for Advanced Simulation, Jülich Center for Hadron Physics, JARA-HPC, JARA-FAME, Forschungszentrum Jülich, Jülich, D-52425, Germany)

21 June 2016

Abstract: The pion–nucleon σ -term can be stringently constrained by the combination of analyticity, unitarity, and crossing symmetry with phenomenological information on the pion–nucleon scattering lengths. Recently, lattice calculations at the physical point have been reported that find lower values by about 3 σ with respect to the phenomenological determination. We point out that a lattice measurement of the pion–nucleon scattering lengths could help resolve the situation by testing the values extracted from spectroscopy measurements in pionic atoms.


Published in: Physics letters B (2016)
Published by: Elsevier
DOI: 10.1016/j.physletb.2016.06.038
License: CC-BY-3.0



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