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

TL;DR

This paper measures the top quark pair production cross section and extracts the top quark mass using dilepton events in proton-antiproton collisions at 1.96 TeV, providing results consistent with previous measurements and theoretical predictions.

Contribution

It presents a new measurement of the top quark pair production cross section and top quark mass using dilepton decay channels at Tevatron energies.

Findings

Measured cross section for top quark pair production: 7.5 pb with uncertainties.

Extracted top quark mass: 171.5 GeV with uncertainties.

Results agree with direct measurements and QCD predictions.

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 +1.0-1.0 (stat) +0.7-0.6 (syst) +0.6-0.5 (lumi) pb. Using lepton+tau events only, we measure: \sigma_ttbar \times B(ttbar to ltau bbbar) = 0.13 +0.09-0.08 (stat) +0.06-0.06 (syst) +0.02-0.02 (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 +9.9-8.8 GeV, in agreement with direct measurements.