QCD Corrections to $\Delta\rho$

Abstract

We discuss a simple method to evaluate the QCD corrections to $\Delta\rho$. It assumes that the perturbative expansion in terms of $\ms$ parameters is meaningful and, unlike other studies, exploits significant available information concerning $\chass$ corrections. This approach leads to an enhancement of $\sim26\%$ relative to the conventional evaluation. QCD corrections to the $Z^0\to b\bar b$ amplitude are also considered. Implications for electroweak physics are briefly discussed.