Identified Hadron Production and Light Quark Fragmentation in Z0 Decays

Abstract

We have measured the differential cross sections for the production of ${\pi }^{+}$, $K^{+}$, $K^0$, $K^{\ast 0}$, $\varphi$, p, $\Lambda$ and their corresponding antiparticles in separate samples of flavor-tagged $Z^0\to$ light-flavor ($u\bar{u}$, $d\bar{d}$, or $s\bar{s}$), $Z^0\to c\bar{c}$ and $Z^0\to b\bar{b}$ events. Clear flavor dependences are observed, and the results are compared with the predictions of three fragmentation models. We have also performed a direct measurement of $A_s$, the parity-violating coupling of the $Z^0$ to strange quarks, by measuring the left-right-forward-backward production asymmetry in polar angle of the tagged $s$ quark. Our preliminary result is $A_s$ = $0.82\pm 0.10(stat.)\pm 0.07(syst.)$.

arXiv comment11 pages, 3 figures, to appear in Proceedings of QCD98 Euroconference, Montpellier, France