Measurement of the Effective Weak Mixing Angle by Jet-Charge Asymmetry in Hadronic Decays of the Z Boson

Abstract

The coupling of the Z boson to quarks is studied in a sample of about 3.5 million hadronic Z decays collected by the L3 experiment at LEP from 1991 to 1995. The forward-backward quark charge asymmet ry is measured by means of a jet charge technique. From the measured asymmetries, the effective weak mixing angle is determined to be \begin{center} $\STE = 0.2327 \pm 0.0012(\mbox{\emph{stat.}} ) \pm 0.0013(\mbox{\emph{syst.}