Measurement of the Top Pair Production Cross Section in the Lepton +   Jets Channel Using a Jet Flavor Discriminant
  We present a new method to measure the top quark pair production cross section and the background rates with 2.7 fb$^{-1}$ of data from $p\bar{p}$ collisions at $\sqrt{s} =1.96$ TeV collected with the CDF II Detector. The size of the dataset was chosen to directly show the improvements of this new method. We select events with a single electron or muon, missing transverse energy, and at least one b-tagged jet. We perform a simultaneous fit to a jet flavor discriminant across nine samples defined by the number of jets and b-tags. We measure a top cross section of $\sigma_{t\bar{t}} = 7.64 \pm 0.57 \mathrm{(stat + syst)} \pm 0.45 \mathrm{(luminosity)}$ pb. An advantage of this approach is that many systematic uncertainties are measured in situ and inversely scale with integrated luminosity. 
T. Aaltonen, B. Alvarez Gonzalez, S. Amerio, D. Amidei, A. Anastassov,   A. Annovi, J. Antos, G. Apollinari, J.A. Appel, A. ...
hep-ex