Aspects of φ-meson production in proton-proton collisions

We analyze near-threshold cross-section data for the reaction pp → ppφ published by the DISTO Collaboration and recent, still preliminary results presented by the ANKE Collaboration. We formulate a procedure to evaluate the OZI ratio at low energies by taking into account corrections from the kinematics and the final-state interaction. Combining the new data with the few measurements available at higher energies we give a limit for the OZI rule violation. We also demonstrate and discuss the effect of a possible contribution from a five-quark baryonic resonance coupled to the φp system on the pp → ppφ cross-section and the φp and pp invariant mass spectra.