Search for High Mass Top Quark Production inpp¯Collisions ats=1.8 TeV

We present new results on the search for the top quark in $p\overline{p}$ collisions at $\sqrt{s}=1.8\mathrm{}$ TeV with an integrated luminosity of $13.5\pm 1.6$ p${\mathrm{b}}^{–1}$. We have considered $t\overline{t}$ production in the standard model using electron and muon dilepton decay channels ( $t\overline{t}\to e\mu +$ jets, $\mathrm{ee}+$ jets, and $\mu \mu +$ jets) and single-lepton decay channels ( $t\overline{t}\to e+$ jets and $\mu +$ jets) with and without tagging of $b$ quark jets. From all channels we have nine events with an expected background of $3.8\pm 0.9$. If we assume that the excess is due to $t\overline{t}$ production, and assume a top mass of 180 GeV/ $c^2$, we obtain a cross section of $8.2\pm 5.1$ pb.