One-loop QCD Corrections to Top Quark Decay into a Neutralino and Light   Stop
  We calculate the one-loop QCD corrections to $t\rightarrow \tilde t_1 \tilde \chi^0_j$ using 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\rightarrow \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 stop case with those in the mixing stop case. 
Chong Sheng Li, Robert J. Oakes and Jin Min Yang