Chi(c) production in hadronic Z decays

Abstract We report on inclusive x c production in Z decays reconstructed via the decay mode X c → J + γ . This analysis is based on 1.1 million hadronic Z events. Interpreting the observed signal as X cl , we obtain a branching ratio Br( Z → X cl + X) = (7.5±2.9(stat.) ±0.6(sys.)) × 10 −3 . Assuming all events are produced in b decays we obtain Br( b → X cl + X) = (2.4 ± 0.9(stat.) ±0.2(sys.)) × 10 −2 . We also present an improved measurement of the branching ratio Br(Z → J + X) = (3.6 ± 0.5 (stat.) ± 0.4 (sys.)) × 10 −3 , obtained from dileptonic J decays.