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

Abstract

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 ${\mathrm{pb}}^{\mathrm{-}1}$, we report results of a search for tt¯ pairs in the decay modes tt¯→eμ+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/${\mathit{c}}^2$ 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.