φ-meson production in pN collisions close to threshold

At the ANKE facility of COSY Jullich, the reactions pp -> pp phi and pn -> d phi have been investigated. Data for the total cross section in the pp entrance channel have been obtained at excess energies of 19 MeV, 35 MeV and 76 MeV. In case of the pn entrance channel the energy dependence of the cross section up to 80 MeV has been extracted by exploiting the intrinsic momentum of the target neutron using a deuterium target. The new 0 data combined with the existing data on omega-meson production provides the phi/omega production ratio in both, the pp- and pn-channels. The ratios of both channels are found to be similar and about eight times larger than the ratio based on Okubo-Zweig-Iizuka (OZI) rule.