Identification of top quarks using kinematic variables.

Abstract

We have used a kinematic technique to distinguish top quark pair production from background in pp\ifmmode\bar\else\textasciimacron\fi{} collisions at \ensuremath{\surd}s=1.8 TeV, applied to 67 ${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$ of data. We define a sample of W+\ensuremath{\ge}3 jet events in which the jets are produced at large angles relative to the incident beams. In this sample, we find an excess of events with large jet transverse energies relative to expectations from background. The excess is consistent with top quark production; a large fraction of events in this kinematic region contains b jets. We interpret these results as evidence that most of the selected events are from tt\ifmmode\bar\else\textasciimacron\fi{} decay.