Spin effects in pion-nucleon and nucleon-nucleon scattering at high energies and fixed angles

Based on the study of the general structure of helicity amplitudes, obligatory kinematic factors are separated and the so-called dynamic amplitudes are introduced. These factors make conservation laws fulfill and contain all the kinematic singularities of helicity amplitudes. Via the dynamic amplitudes, the observable quantities are expressed in a simple form. Kinematic factors play the role of weighting functions. At high energies and fixed angles these factors turn into small parameters which suppress contributions of some helicity amplitudes, and enhance contributions of others. So we get the kinematic hierarchy for binary processes. As an example we consider πN- and NN-scattering. Predictions are given for some asymmetry parameters which do not coincide with the helicity conservation rules, predicted by QCD