OZI violation and polarization effects in the nucleon-nucleon induced production of vector mesons

Polarization phenomena for vector meson production in the processes N + N → N + N + V0 near threshold are studied in order to shed light on the s anti s-component in the nucleon. The spin structure of the threshold amplitudes of the processes p + p → p + p + V0 and n + p → n + p + V0 are derived and polarization effects are predicted in a very general formalism, without any hypothesis on the reaction mechanism, using only symmetry properties of strong interactions. It is shown that in pp-interactions at threshold polarization observables do not contain any new information about s anti s-component in the nucleon, with respect to the cross section with unpolarized particles. In np-interactions the threshold vector meson production can be characterized by a triplet and singlet spin amplitudes which should act differently in φ- and ω- production. (authors). 24 refs., 1 fig