A. Gasparyan

Pion nucleon scattering in a meson exchange model

The pN interaction is studied within a meson-exchange model and in a coupled-channels approach which includes the channels pN, hN, as well as three effective ppN channels, namely, rN, pD, andsN. Starting out from an earlier model of the Jülich group systematic improvements in the dynamics and in some technical aspects are introduced. With the new model an excellent quantitative reproduction of the pN phase shifts and inelasticity parameters in the energy region up to 1.9 GeV and for total angular momenta Jø3/2 is achieved. Simultaneously, good agreement with data for the total and differential pN→hN transition cross sections is obtained. The connection of the pN dynamics in theS11 partial wave with the reaction pN→hN is discussed.

How to extract the Lambda N scattering length from production reactions

A dispersion integral is derived that allows one to relate directly (spin dependent)

Extraction of scattering lengths from final-state interactions

\Lambda N

Production of eta mesons in nucleon-nucleon collisions

invariant mass spectra, measured in a large-momentum transfer reaction such as

Scattering lengths of strangeness S=-2 baryon-baryon interactions

pp\to K^+p\Lambda

ΛN scattering length from the reaction γd→K+Λn

or

Lambda N scattering length from the reaction gamma d -> K+Lambda n

\gamma d\to K^+n\Lambda

Λ N scattering length from the reaction γ d→K + Λ n

, to the scattering length for elastic

Production of η mesons in nucleon-nucleon collisions

\Lambda N

Production of ? mesons in nucleon-nucleon collisions

scattering. The involved systematic uncertainties are estimated to be smaller than 0.3 fm. This estimate is confirmed by comparing results of the proposed formalism with those of microscopic model calculations. We also show, for the specific reaction