Flavor-changing top quark decays inR-parity-violating supersymmetric models

The flavor-changing top quark decays $\overrightarrow{t}\mathrm{cV}$ $(V=Z,\gamma ,g)$ induced by R-parity-violating couplings in the minimal supersymmetric standard model are evaluated. We find that the decays $\overrightarrow{t}\mathrm{cV}$ can be significantly enhanced relative to those in the R-parity-conserving supersymmetric model. Our results show that the top quark flavor-changing neutral current decay can be as large as $\mathrm{Br}\left(\overrightarrow{t}cg\right)\sim {10}^{-3},$ $\mathrm{Br}\left(\overrightarrow{t}cZ\right)\sim {10}^{-4},$ and $\mathrm{Br}\left(\overrightarrow{t}c\gamma \right)\sim {10}^{-5},$ which may be observable at the upgraded Fermilab Tevatron and/or the CERN LHC.