Measurement of the ttbar production cross section and top quark mass extraction using dilepton events in ppbar collisions

Abstract

We present a measurement of the top quark pair production cross section in ppbar collisions at sqrt{s}=1.96 TeV using approximately 1 fb^{-1} of data collected with the D0 detector. We consider decay channels containing two high pt charged leptons where one lepton is identified as an electron or a muon while the other lepton can be an electron, a muon or a hadronically decaying tau lepton. For a mass of the top quark of 170 GeV, the measured cross section is 7.5 _s161.0-1.0 (stat) _s160.7-0.6 (syst) _s160.6-0.5 (lumi) pb. Using lepton_s16tau events only, we measure: sigma_ttbar times B(ttbar to ltau bbbar) = 0.13 _s160.09-0.08 (stat) _s160.06-0.06 (syst) _s160.02-0.02 (lumi) pb. Comparing the measured cross section as a function of the mass of the top quark with a partial next-to-next-to leading order Quantum Chromodynamics theoretical prediction, we extract a mass of the top quark of 171.5 _s169.9-8.8 GeV, in agreement with direct measurements.