SINGLE-TOP-QUARK PRODUCTION AT HADRON COLLIDERS - ART. NO. 094021

Single-top-quark production probes the charged-current weak interactio n of the top quark, and provides a direct measurement of the CKM matri x element V-tb. We perform two independent analyses to quantify the ac curacy with which the W-gluon fusion (gq--><t(b)over bar>q and <q(q)ov er bar>--><t(b)over bar> 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 W-gluon fusion (b) over bar differential cross section, we show how to obtain a relia ble cross section integrated over low (b) over bar transverse momenta up to a cutoff. We estimate the accuracy with which V-tb can be measur ed in both analyses, including theoretical and statistical uncertainti es. We also show that the polarization of the top quark in W-gluon fus ion can be detected at the Fermilab Tevatron and the CERN LHC. [S0556- 2821(98)08821-3]