One-loop QCD corrections to top quark decay into a neutralino and light stop squark

We calculate the one-loop QCD corrections to $t\to {\tilde{t}}_1{\tilde{\chi }}_j^0$ using the dimensional reduction scheme, including QCD and supersymmetric QCD corrections. The analytic expressions for the corrections to the decay width are given, which can easily be extended to $t\to {\tilde{\chi }}_j^{+}{\tilde{b}}_i$. The numerical results show that the correction amounts to more than a 10% reduction in the partial width relative to the tree level result. We also compare the corrections in the no-mixing top squark case with those in the mixing top squark case.