Nucleon structure and pion-phenomena

Abstract

The effect of the nucleon structure is discussed correlating phenomenologically a variety of pion-nucleon phenomena with the nucleon core. In the high energy region, the various experimental evidence is interpreted in terms of nucleon structure. The main results are: 1) The optical radiusR of the proton estimated from the π−-p elastic scattering is nearly constant in the energy region (1÷5) GeV. 2) The effective collision parameter in the π−-p reaction shows the nearly constant value 0.8·1013 cm in the (1÷5) GeV region. 3) The mean energy of the mesons produced in the π+-p reaction in the energy range (1÷5) GeV indicates a picture of meson production as a shaking off of mesons from the nucleon core. 4) In the nucleon-nucleon collision in GeV order, the mean neergy of the produced mesons suggests a shaking off of the external meson cloud such as given by the isobar model. 5) A regularity of the reduced multi-plicity is discussed concerning the proton-antiproton annihilation star. In the low energy region, the well known failure of the meson theory on theS wave is to be ascribed to the internal effect of the nucleon structure (Appendix).