Test of the Zweig rule in π−p interactions at 19 GeV/c

Abstract We have observed φ production in π − p interactions at 19 GeV/ c with (44±10) events in the final state φπ + π − π − p and (45±9) events in φ K + K − π − p. The production ratios φπ + π − π − p/ ωπ + π − π − p ≈ 0.005 and φ K + K − π − p/ ϱ °K + K − π − p ≈ 0.45 agree with Zweig-rule expectations.