More on higher order decays of the lighter top squark

We discuss the three-body decays $t_1\to W^{+}b{\tilde{\chi }}_1^0,$ $t_1\to H^{+}b{\tilde{\chi }}_1^0,$ $t_1\to b{l}_i^{+}{\nu }_l,$ and $t_1\to b{\tilde{\nu }}_l{l}^{+}(l=e,\mu ,\tau )$ of the lighter top squark $t_1$ within the minimal supersymmetric standard model. We give the complete analytical formulas for the decay widths and present a numerical study in view of an upgraded Fermilab Tevatron, the CERN LHC, and a future lepton collider demonstrating the importance of these decay modes.