We analyze the rare and flavor changing decay of the top quark into a charm quark and a gauge boson in the littlest Higgs model with T-parity (LHT). We calculate the one-loop level contributions from the T-parity odd mirror quarks and gauge bosons. We find that the decay $t\to c V, (V=g,\gamma,Z)$ in the LHT model can be significantly enhanced relative to those in the Standard Model. Our numerical results show that the top quark FCNC decay can be as large as $Br(t\to cg)\sim 10^{ -2}$, $Br(t\to cZ)\sim 10^{ -5}$ and $Br(t\to c\gamma)\sim 10^{ -7}$ in the favorite parameter space in the LHT model.
Categories: hep-ph