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 ss̄ quark pairs in the nucleon wave function enables the direct coupling to the φ-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 ss̄ sea-quark component, kaon-hyperon clusters based on a simple chiral quark model, and the pentaquark picture uudss̄. Nonrelativistic quark model calculations reveal that the strangeness magnetic moment μs and the strangeness contribution to the proton spin σs from the first two models are consistent with recent experimental data, where μs and σs are negative. For the third model, the uuds subsystem with the configurations FSFS and FS FS leads to negative values of μs and σs. With effective quark line diagrams incorporating the P03 model, we give estimates for the branching ratios of the annihilation reactions at rest pp̄→φX (X=π0, η, ρ0, ω). Results for the branching ratios of φX production from atomic pp̄ s-wave states are for the first and third model found to be strongly channel dependent, in good agreement with measured rates.
|Журнал||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Состояние||Опубликовано - 27 окт 2011|
|Опубликовано для внешнего пользования||Да|
ASJC Scopus subject areas
- Nuclear and High Energy Physics