Tevatron combined single top production cross sections

Abstract

This paper reports the most recent measurements of the cross sections for the two main production modes of single top quarks in pp collisions at a center-of-mass energy of 1.96 TeV in the Run II data collected with the CDF and D0 detector at the Fermilab Tevatron Collider. For this measurement the full data set corresponding to an integrated luminosity of up to 9.7 fb−1 per experiment is used. We report the first observation of single top quark production in the s-channel with a significance of 6.3 standard deviations. We also present a simultaneous measurement of the production cross section of tand s+t-channels. Using these measurements we set a lower limit on the CKM matrix element |Vtb| > 0.92 at 95% C.L., assuming mt = 172.5 GeV. Moreover, we present a search for charged massive resonances decaying to top (t) and bottom (b) quarks performed at CDF in the same data set. No significant excess above the standard model (SM) background prediction is observed and constraints on the W ′→ tb mass and couplings in the 300 to 900 GeV/c2 range are set.