No abstract available

No abstract available

[en] We show that the GLM model, along with a prescription implementing the unitarity condition, perfectly describes the complete (real and imaginary) s- and p-wave π-N amplitude from threshold up to the 33-resonance region, including the π-N Σ-term. (orig.)

[en] In this paper an optimal state analysis of pion-nucleon elastic scattering data is presented. Then, it is shown that the optimal state predictions are experimentally satisfied to a surprising accuracy even for a single optimal state description of pion-nucleon elastic scattering, for all p_LAB higher then 3 GeV/c. The optimal state analysis as an important alternative to the phase shift analysis is discussed. (Author)

[en] Kisslinger and cut-off Kisslinger off-shell scattering amplitudes are compared with the result of a dispersion-theory calculation. It is concluded that the meson--nucleon finite range is less than 1/3 fm. 1 figure

[en] The scattering operator of a 'pion' on two 'nucleons' is evaluated in the Lee model and is shown to be identical to the results of the Watson's multiple scattering theory

[en] A review is given of recent developments in the study of the pion-nucleus interaction. Knowledge gained from experiments concerning the reaction mechanism and the influence of the nuclear environment on the pion interaction is discussed. The similarity of the physics deduced from multiple scattering theories, isobar-hole formulations and field theory models is indicated, and the importance of multi-nucleon effects is emphasized. (orig.)

No abstract available

[en] Research on pion--nucleon interactions and mesonic atoms is summarized

[en] The pion is an hadronic probe with many facets. The multiple research aspects contain complex interconnections. In an attempt to present some of the developments in pion-nucleus physics, the authors separated the field into areas closely associated with specific goals. The inherent danger in such an approach is clear: the reader's attention may be too narrowly focused and important collateral observations missed. This danger is largely offset by the advantage of giving the reader a thread to follow. Thus, the authors present a series of minireviews, each one largely independent of the others, along with the basic physics background needed by a nonexpert. Each topic is worthy of a separate review, but they seek to gather here an overview of the field