Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element $\bf V_{tb}$

Abstract

We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb$^{-1}$ per experiment. The $t$-channel cross section is measured to be $\sigma_t = 2.25^{+0.29}_{-0.31}$ pb. We also present the combinations of the two-dimensional measurements of the $s$- vs. $t$-channel cross sections and of the $s+t$ channel cross section measurement resulting in $\sigma_{s+t} = 3.30^{+0.52}_{-0.40}$ pb, without assuming the standard-model value for the ratio $\sigma_s/\sigma_t$. The resulting value of the magnitude of the top-to-bottom quark coupling is $|V_{tb}|$ = $1.02^{+0.06}_{-0.05}$, corresponding to $|V_{tb}| > 0.92$ at the 95% C.L.