Top-quark signatures at the Fermilab Tevatron collider

Abstract

Calculations are presented for the experimental signals arising from top-quark production in pp¯ collisions with semileptonic top decay, for the center-of-mass energy √s =2 TeV available at the Fermilab Tevatron. Both the strong production of tt¯ pairs via QCD and the electroweak channels $W^{+}$→tb¯, $W^{\mathrm{-}}$→bt¯ are considered, including gluon bremsstrahlung effects and complete cascade decays of heavy quarks. To separate the t signal from bb¯, cc¯, bb¯bb¯, W, Z, and other backgrounds, we require events containing an isolated lepton along with n jets (n≥2). The top mass may be determined by the three-jet invariant mass, or a transverse mass formed from the lepton, third hardest jet, and missing $p_T$. For $m_t$≲80 GeV, confirmation of this signal may be obtained from observation of events containing two isolated leptons at high $p_T$. From these results, we expect the upcoming run of the Fermilab Tevatron collider to be able to probe t masses up to $m_t$=100 GeV, assuming sufficient detector resolution.