Lower limit on the top-quark mass from events with two leptons in<i>pp¯</i>collisions at √<i>s</i>=1.8 TeV

Abstract

We present results from searches for the top quark pp\ifmmode\bar\else\textasciimacron\fi{} collisions at the Fermilab Tevatron Collider. The data sample was collected during 1988--89 with the Collider Detector at Fermilab and has an integrated luminosity of 4.1 ${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$. Our previous search for e\ensuremath{\mu} final states for tt\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\rightarrow}e\ensuremath{\nu}b \ensuremath{\mu}\ensuremath{\nu}b\ifmmode\bar\else\textasciimacron\fi{} decays has been extended to include the ee and \ensuremath{\mu}\ensuremath{\mu} channels. In addition, we have searched in each event with a high-transverse-momentum lepton accompanied by hadron jets for a low-transverse-momentum muon as a tag of a bottom quark in tt\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\rightarrow}l\ensuremath{\nu}bqq\ifmmode\bar\else\textasciimacron\fi{}b\ifmmode\bar\else\textasciimacron\fi{} decays. A lower limit on the top-quark mass of 91 GeV/${\mathit{c}}^{2}$ is obtained at the 95% confidence level, assuming standard model decays.