Width and flavor-changing decays of the Z as a test of exotic quarks and leptons

Abstract

With the advent of the SLAC Linear Collider and the CERN e⁺e⁻ collider LEP, precision measurements of the width and the flavor-changing decays of the Z boson will soon be available. We evaluate the effect on these quantities of the mixing of heavy exotic quarks and leptons with the usual ones. The mixing angles are constrained from the forward-backward charge-asymmetry measurements. We find that the Z width is usually smaller than the standard-model value and the flavor-changing decays are large enough to be detectable.