Search for the standard model Higgs boson produced in association with top quarks at CDF

We present a preliminary search for the standard model Higgs boson produced in association with a top quark pair using the CDF II detector at the Fermilab Tevatron in 5.1 fb$^{-1}$ of data. We consider events which have only one identified charged lepton, an imbalance in transverse momentum, and at least five jets, where at least two of these jets are consistent with originating from the decay of a $B$ hadron. Using a neural network technique, we place preliminary 95\% confidence level upper limits on the $ttH$ production cross section for a range of Higgs boson masses. Further efforts to improve the sensitivity of our search through increased signal acceptance and additional background discrimination are also described.