Search for Flavor-Changing Neutral Current Decays of the Top Quark inpp¯Collisions ats=1.8TeV

We search for the flavor-changing neutral current decays of the top quark $t\ensuremath{\rightarrow}q\ensuremath{\gamma}$ and $t\ensuremath{\rightarrow}\mathrm{qZ}$ (here $q$ represents the $c$ and $u$ quarks) in $\overline{p}p$ collisions at $\sqrt{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.8\phantom{\rule{0ex}{0ex}}\mathrm{TeV}$. We use a dataset $(\ensuremath{\int}L\mathrm{dt}\ensuremath{\sim}110{\mathrm{pb}}^{\ensuremath{-}1})$ collected during the 1992--1995 run of the Collider Detector at Fermilab. We set 95% confidence level limits on the branching fractions $B(t\ensuremath{\rightarrow}q\ensuremath{\gamma})l3.2%$ and $B(t\ensuremath{\rightarrow}\mathrm{qZ})l33%$, consistent with the standard model.