# Measurement of the s-channel Single Top Quark Cross Section at the CDF Experiment and Contributions to the Evidence of H->bb at the Tevatron

Author:
Liu, Hao, Physics - Graduate School of Arts and Sciences, University of Virginia
In this thesis, we present the measurement of the s-channel single top quark production cross section. In the cross section measurement we use data generated by proton-antiproton collisions at the center-of-mass energy $\sqrt{s}= 1.96$ TeV and collected by the CDF Run II detector. The total data set corresponds to an integrated luminosity of 9.4 fb^-1. We select events consistent with the s-channel process including two jets identified as originating from b quarks and one leptonically decaying W boson. The observed significance is 3.8 standard deviations with respect to the background-only hypothesis. Assuming a top-quark mass of 172.5 GeV/c^2, we measure the s-channel cross section to be 1.41^{+0.44}_{-0.42} pb. When combined with other measurements at the CDF and D0 experiments, the observed significance increases to 6.4 standard deviations, which is interpreted as the first observation of the single top quark s-channel production process.