CDF top-quark kinematical analyses

Summary

We analyze a sample of W+jet events collected with the Collider Detector at Fermilab (CDF) in p$\bar p$ collisions at √s=1.8 TeV to study t$\bar t$ production. We employ a simple kinematical variable ℋ, defined as the scalar sum of the transverse energies of the lepton, neutrino and jets. For events with a W boson and four or more jets, the shape of the ℋ distribution deviates by 3.8 standard deviations from that expected from known backgrounds to t$\bar t$ production. However this distribution agrees well with a linear combination of background and t$\bar t$ events, the agreement being best for a top mass of 180 GeV/c². We also find an excess of events with large jet transverse energies relative to expectations from background. The excess is consistent with top production.