NORMALIZATION OF QCD CORRECTIONS IN TOP-QUARK DECAY

We discuss the effects of QCD corrections to the on-shell decay t --> bW. We resolve the scale ambiguity using the Brodsky-Lepage-Mackenzie scheme, and find that the appropriate coupling constant is a(s)MSBAR(0 .122m(t)). The largest long distance contribution comes from the defin ition of the on-shell mass of the top quark. We note that QCD correcti ons to the electroweak rho parameter are extremely small when the rho parameter is expressed in terms of the top quark width.