Abstract

Apparent channel-dependent violations of the Okubo-Zwieg-Iizuka (OZI) rule in nucleon-antinucleon annihilation reactions in the presence of an intrinsic strangeness component in the nucleon are discussed. Admixture of s (s) over bar quark pairs in the nucleon wave function enables the direct coupling to the phi-meson in the annihilation channel without violating the OZI rule. Three forms are considered in this work for the strangeness content of the proton wave function, namely, the uud cluster with a s (s) over bar sea-quark component, kaon-hyperon clusters based on a simple chiral quark model, and the pentaquark picture uuds (s) over bar. Nonrelativistic quark model calculations reveal that the strangeness magnetic moment mu(s) and the strangeness contribution to the proton spin sigma(s) from the first two models are consistent with recent experimental data, where mu(s) and sigma(s) are negative. For the third model, the uuds subsystem with the configurations [31](FS)[211](F)[22](S) and [31](FS)[31](F)[22](S) leads to negative values of mu(s) and sigma(s). With effective quark line diagrams incorporating the P-3(0) model, we give estimates for the branching ratios of the annihilation reactions at rest p (p) over bar -> phi X (X = pi(0), eta, rho(0), omega). Results for the branching ratios of phi X production from atomic p (p) over bar s-wave states are for the first and third model found to be strongly channel dependent, in good agreement with measured rates.