Single-top-quark production at hadron colliders

Single-top-quark production probes the charged-current weak interaction of the top quark, and provides a direct measurement of the CKM matrix element (Formula presented) We perform two independent analyses to quantify the accuracy with which the (Formula presented)-gluon fusion (Formula presented) and (Formula presented) signals can be extracted from the backgrounds at both the Fermilab Tevatron and the CERN LHC. Although perturbation theory breaks down at low transverse momentum for the (Formula presented)-gluon fusion (Formula presented) differential cross section, we show how to obtain a reliable cross section integrated over low (Formula presented) transverse momenta up to a cutoff. We estimate the accuracy with which (Formula presented) can be measured in both analyses, including theoretical and statistical uncertainties. We also show that the polarization of the top quark in (Formula presented)-gluon fusion can be detected at the Fermilab Tevatron and the CERN LHC.