MEASUREMENT OF CHARGE ASYMMETRY IN HADRONIC Z DECAYS

A significant charge asymmetry is observed in the hadronic Z decays collected with the ALEPH detector at LEP. The asymmetry expressed in terms of the difference in momentum weighted charges in the two event hemispheres is measured to be <Q(forward)> - <Q(backward)> = - 0.0084 +/- 0.0015 (stat.) +/- 0.0004 (exp. sys.). In the framework of the standard model this can be interpreted as a measurement of the effective electroweak mixing angle, sin2-theta-w(M(z)2) = 0.2300 +/- 0.0034 (stat.) +/- 0.0010 (exp. sys.) +/- 0.0038 (theor. sys.) or of the ratio of the vector to axial-vector coupling constants of the electron, g(v(e))/g(A(e)) = + 0.073 +/- 0.024.