Measurement of Leading Particle Effects in Decays ofZ0Bosons into Light Flavors

We present evidence for leading particle production in hadronic decays of the $Z^0$ boson to light-flavor jets. A polarized electron beam was used to tag quark and antiquark jets, and a vertex detector was employed to reject heavy-flavor events. Charged hadrons were identified with a Cherenkov ring imaging detector. In the quark jets, more high-momentum $p$, $\Lambda$, $K^{-}$, and ${\overline{K}}^{*0\mathrm{}}$ were observed than their antiparticles, and vice versa for antiquark jets, providing direct evidence that the higher-momentum particles in jets are more likely to carry the primary quark or antiquark from the $Z^0$ decay, and that $s\overline{s}$ production is suppressed in fragmentation.