Determination of the real part of the isospin-even forward-scattering amplitude of pion-nucleon scattering at 55 MeV as a test of low-energy quantum chromodynamics
- 16 February 1987
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 58 (7), 648-650
- https://doi.org/10.1103/physrevlett.58.648
Abstract
The real part of the isospin-even forward-scattering amplitude of pion-nucleon scattering has been determined at a pion energy of =55 MeV by measurement of the elastic scattering of positive and negative pions on protons within the Coulomb-nuclear interference region. The value confirms the prediction of the Karlsruhe-Helsinki phase-shift analysis for that energy. These phases have been used to determine the σ term of pion-nucleon scattering by means of dispersion relations, resulting in a value for σ which is in contradiction with chiral perturbation theory of QCD.
Keywords
This publication has 8 references indexed in Scilit:
- Chiral perturbation theory and effective lagrangiansNuclear Physics B, 1987
- A new determination of the π−H and π−D 2P-1s strong interaction shifts using crystal diffractionPhysics Letters B, 1985
- Quark massesPhysics Reports, 1982
- A new determination of the πN sigma term using hyperbolic dispersion relations in the (ν2,t) planeThe European Physical Journal C, 1982
- Low-energy πN partial wave analysisNuclear Physics A, 1980
- Nonanalytic Behavior of theTerm inScatteringPhysical Review D, 1971
- The σ term and low-energy π-N scatteringNuclear Physics B, 1971
- Adler-Weisberger Theorem ReexaminedPhysical Review D, 1971