Abstract
We present a calculation of the next-to-leading-order QCD corrections, with the one-scale phase space slicing method, to single top quark production and decay process pp¯,pptb¯+Xbνb¯+X at hadron colliders. Using the helicity amplitude method, the angular correlation of the final state partons and the spin correlation of the top quark are preserved. The effect of the top quark width is also examined.