Flavor-changing decays of theZ0and leptoquarks

Many extensions of the standard model, e.g., certain composite models and some superstring- inspired'' E{sub 6} models, contain new scalar matter fields which couple to both quarks and leptons, i.e., leptoquarks. We consider leptonic flavor-changing decays of the {ital Z}{sup 0}, e.g., {ital Z}{sup 0}{r arrow}{mu}{sup +}{tau}{sup {minus}}, due to one-loop diagrams involving such leptoquarks. We find branching ratios which are at most {approx}10{sup {minus}7}, even assuming generous values for unknown Yukawa couplings.