We present the single top quark analysis in lepton plus jets final state using 7.5 fb^-1 of pp collision data collected by CDF Run II experiment. We select events in the W + jets topology consistent with the signature of a charged lepton (electron or muon), large missing transverse energy from the W boson decay and two or three jets, at least one of them is required to be identified as originating from a bottom quark. We use the new POWHEG Monte Carlo generator for single top signal samples in s-channel, t-channel and Wt-channel, which are extended at NLO accuracy, with an assumed top quark mass of 172.5 GeV/c². The Neural Network multivariate method is used to discriminant signal from comparatively large backgrounds. We measure a cross section of 3.04^+0.57_-0.53 (stat. + syst.) pb and extract the CKM matrix element value V_tb=0.96 ± 0.09(stat. + syst.) ± 0.05(theory). We obtain a 95% confidence level lower limit of V_tb > 0.78.

Public note

The results should be considered preliminary until published in a refereed journal. They can be used in conference presentations with proper reference to the CDF Collaboration.