Dittmann, Jay R.Wu, Zhenbin, 1984-The Collider Detector at Fermilab Experimental Collaboration.2013-05-152013-05-152012-122013-05-15http://hdl.handle.net/2104/8604We present a measurement of the single top quark cross section in the lepton plus jets final state using an integrated luminosity corresponding to 7.5/fb of collision data collected by the Collider Detector at Fermilab. The single top candidate events are identified by the signature of a charged lepton, large missing transverse energy, and two or three jets with at least one of them identified as originating from a bottom quark. A new Monte Carlo generator powheg is used to model the single top quark production processes, which include s-channel, t-channel, and Wt-channel. A neural network multivariate method is exploited to discriminate the single top quark signal from the comparatively large backgrounds. We measure a single top production cross section of 3.04+0.57−0.53 (stat. + syst.) pb assuming mtop = 172.5 GeV/c^2. In addition, we extract the CKM matrix element value |Vtb| = 0.96 ± 0.09 (stat. + syst.) ± 0.05 (theory) and set a lower limit of |Vtb| > 0.78 at the 95% credibility level.en-USBaylor University theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact librarywebmaster@baylor.edu for inquiries about permission.High energy physics.Single top quark.Cross section measurement.ThesisWorldwide access.Access changed 5/21/14.