Supersymmetric QCD corrections to the W-boson width

We calculate the one-loop supersymmetric QCD corrections to the width of the $W$-boson. We find that these are of order $\sim {{ \alpha_s} \over {\pi}} {1 \over 20} { {M^2_W} \over {M_S^2}} \Gamma_{u {\bar d}}$, where $M_S$ is the supersymmetry breaking scale and $\Gamma_{u {\bar d}}$ the tree level hadronic width for $W^+ \rightarrow u {\bar d}$. Due to the appearance of the suppression factor $\sim {1 \over 20}$ these are at least two orders of magnitude smaller than the standard QCD corrections $\sim {{ \alpha_s} \over {\pi}} \Gamma_{u {\bar d}}$ and hence of the order of the two-loop electroweak effects. Therefore supersymmetric QCD corrections will only be of relevance once experiments reach that level of accuracy.