Measurement of the $t\bar{t}$ Production Cross Section in the Lepton+Jets Channel with Lifetime Tagging

We present a measurement of the $t\bar{t}$ production cross section at a center-of-mass energy of 1.96 TeV. This analysis is based on the selection of events with one charged lepton (electron or muon), missing transverse energy, and 3 or more jets with $p_T > 20$ GeV and $|\eta| < 2.5 $. We utilize the e+jets (913 pb$^{-1}$) and $\mu$+jets (871 pb$^{-1} $) data samples collected using the D\O\ detector. To help distinguish the signal from the background processes, we use a Neural Network algorithm that uses lifetime information to identify the b-quark jets that are associated with top quark decays. We require at least one b- tagged jet to be identified in this analysis.