Polarization phenomena for meson production in nucleon-nucleon collisions

We analyze polarization phenomena for pseudoscalar and vector mesons production in nucleon-nucleon collisions. We identify three energy regions corresponding to different physics and different approaches in the analysis of polarization effects. In the threshold region, characterized by the S-wave production for all final particles, the general symmetry properties of strong interaction can be applied. The region of intermediate energies, T=2-4 GeV, is characterized by the essential role of central i.e. non-peripheral collisions, where only a small number of s-channel states with definite quantum numbers, ${\cal J}^P=1^-$ and $2^+$, contribute. At higher energies, T $\ge $10 GeV, the leading mechanism is the diffractive dissociation and it is especially interesting for baryon spectroscopy. The transition to this region is an open field for experimental research at the Nuclotron.