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

Large violations of the OZI-rule have been observed in pp-annihilation into φ mesons when the initial state is in triplet spin configuration. One possible explanation for this phenomenon is that this is due to a small negatively polarized ss-component in the nucleon which has been found in polarized deep inelastic scattering of leptons. In the nonperturbative region there is little experimental information on the sign of Δs. We show by spin projection conservation arguments that if the φ-production enhancement in the pp→φπ is due to the transfer of a ss from the initial nucleon to the final φ, then Δs must be preferentially positive. We study polarization phenomena in the process N+N→N+N+V0 where V0 is a vector meson near threshold and we show that a comparison of the pp→ppφ reaction (which is dominated by a spin triplet in the initial state, at threshold) and the np → npφ (which is driven by non-interfering spin triplet and spin singlet amplitudes) would test quantitatively the ss-driven spin triplet dominance. Finally we discuss the possibility of using the relationship between the Gerasimov-Drell-Hearn sum-rule and the integral of the spin structure function g1p to measure the polarization of the ss-component at low momentum transfer. (orig.)