Measurement of the tt¯ production cross section in pp¯ collisions at s=1.96TeV using lepton + jets events with lifetime b-tagging

We present a measurement of the top quark pair (tt¯) production cross section (σtt¯) in pp¯ collisions at s=1.96TeV using 230 pb−1 of data collected by the DØ experiment at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), missing transverse energy, and jets in the final state. We employ lifetime-based b-jet identification techniques to further enhance the tt¯ purity of the selected sample. For a top quark mass of 175 GeV, we measure σtt¯=8.6−1.5+1.6(stat.+syst.)±0.6(lumi.)pb, in agreement with the standard model expectation.