ϕ-Meson Production in the Reactionsπ±N→K−K+Nat 6 GeV/c

Abstract

A sample of 1200 $\varphi$ mesons produced in the Zweig-rule-forbidden reactions ${\pi }^{\pm }N\to \varphi N$ shows a flat $t$ distribution (slope=1.7 ± 0.2 Ge${\mathrm{V}}^{-2\mathrm{}}$) and a cross section suppressed by 0.0032±0.0004 relative to ${\pi }^{-}p\to \omega n$. Natural-parity-exchange $\omega$ and $\varphi$ production have similar $t$ dependences, while $\omega$ and $\varphi$ production by unnatural-parity exchange differ markedly. Interference between the $\varphi$ and the underlying $\overline{K}K$ $S$ wave indicates substantial nucleon-spin incoherence between the amplitudes for $\varphi$ and $S$-wave production.