Evidence for s-Channel Single-Top-Quark Production in Events with One Charged Lepton and Two Jets at CDF

Abstract

We report evidence for s-channel single-top-quark production in proton-antiproton collisions at center-of-mass energy vs=1.96 TeV using a data set that corresponds to an integrated luminosity of 9.4 fb-1 collected by the Collider Detector at Fermilab. We select events consistent with the s-channel process including two jets and one leptonically decaying W boson. The observed significance is 3.8 standard deviations with respect to the background-only prediction. Assuming a top-quark mass of 172.5 GeV/c2, we measure the s-channel cross section to be 1.41+0.44-0.42 pb.