Study of the OZI selection rule in hadronic processes

In the experiments with LEPTON-F and SPHINX spectrometers the pion-induced charged exchange reactions π- + p → ϕ + n and π- + p → ω + n at Pπ-=32.5 GeV, as well as proton-induced diffractive reactions p + N → [pϕ] + N and p + N → [pω] + N at E p =70 GeV were studied. The comparison of the cross-sections for ϕ and ω-production in these reactions is used for testing the OZI selection rule in hadronic processes. It has been demonstrated that in pion reactions the ratio of the yields of ϕ and ω-mesons R(ϕ/ω) = (3 ± 1) · 10−3 is in a good agreement with naive quark model prediction based on the mixing in vector meson nonet and on the OZI rule (R(ϕ/ω)ozi = tg 2Δθ V − 4 · 10−3). At the same time in proton reactions the effective ratio of ϕ and ω yields is ∼ (4 ÷ 7) · 10-2, i.e. a strong violation of the OZI rule is observed in proton-nucleon interactions. This violation can be in favor of possible existence of some exotic ss component in the quark structure of protons.