Search for the top quark inpp¯collisions at √s=1.8 TeV

We have searched for evidence of top quark production in pp{} collisions at {}s =1.8 TeV using the D0 detector at the Fermilab Tevatron collider. For an integrated luminosity of 15 pb^-1, we report results of a search for tt{} pairs in the decay modes tt{}{→}e{μ}+jets,ee+jets,e+jets, and {μ}+jets. From analyses of these modes we obtain a lower limit on the top quark mass of 131 GeV/c² at the 95% confidence level, assuming standard model branching fractions and a predicted cross section for tt{} production. We discuss the properties of an event for which expected backgrounds are small.