Top-quark decay via the anomalous couplingt¯cγat hadron colliders

We determine the constraints on the anomalous top-quark coupling associated with the flavor-changing neutral current vertex $\overline{t}c\gamma$ from the limits on the $b$-quark rare decay $b\to s\gamma$ and nonstandard top-quark decays. Based on these constraints, we discuss the experimental observability of the rare decay mode $t\to c\gamma$, both at the Fermilab Tevatron with a luminosity upgrade and at the CERN LHC.