Production of pi(+), K+, K-0, K*(0), phi, p and Lambda(0) in hadronic Z(0)decays - art. no. 052001

We have measured the differential production cross sections as a function o f scaled momentum x(p)=2p/E-c.m. of the identified hadron species pi(+), K, K-0, K-*0, phi, p, Lambda(0), and of the corresponding antihadron species in inclusive hadronic Z(0) decays, as well as separately for Z(0) decays i nto light (u, d, s), c and b flavors. Clear flavor dependences are observed , consistent with expectations based upon previously measured production an d decay properties of heavy hadrons. These results were used to test the QC D predictions of Gribov and Lipatov, the predictions of QCD in the modified leading logarithm approximation with the ansatz of local parton-hadron dua lity, and the predictions of three fragmentation models. The ratios of prod uction of different hadron species were also measured as a function of x(p) and were used to study the suppression of strange meson, strange and non-s trange baryon, and vector meson production in the jet fragmentation process . The light-flavor results provide improved tests of the above predictions, as they remove the contribution of heavy hadron production and decay from that of the rest of the fragmentation process. In addition we have compared hadron and antihadron production as a function of x(p) in light quark (as opposed to antiquark) jets. Differences are observed at high x(p), providin g direct evidence that higher-momentum hadrons are more likely to contain a primary quark or antiquark. The differences for pseudoscalar and vector ka ons provide new measurements of strangeness suppression for high-x(p) fragm entation products. [S0556-2821(99)06101-9].