Search for single top quark production at CDF using a matrix element method

We present recent results from searches for single-top-quark production using 2 fb$^{-1}$ of data accumulated with the CDF detector at the Fermilab Tevatron. We select events with one charged lepton, large missing transverse energy, and two jets, where one jet is identified as a b-quark jet using displaced secondary-vertex information from the CDF silicon detector. We employ a matrix-element analysis technique and a neural-network jet-flavor separator to improve separation of signal and background and greatly improve the sensitivity of our search.