Annihilation into Channels with Strangeness and the OZI Rule Violation

Abstract

Two-step mechanisms in the $N\bar{N}$ annihilation and their role in the OZI rule violating reactions are discussed. In particular the two meson rescattering mechanism for $πϕ$ channel including all off-shell effects is typically two orders of magnitude bigger than the OZI tree level expectation and explains the observed ratio $ϕπ/ωπ$ in the annihilation at rest. The rates for the final states including photons, $γω$ and $γϕ$, can be explained in the vector dominance model. The observed rate for $p\bar{p}\toγω$ is suppressed due to destructive interference between the intermediate $ρ$ and $ω$ states while the interference in $p\bar{p}\toγϕ$ is required to be constructive leading to a large ratio $γϕ/γω$.