Search for Top-Quark Production via Flavor-Changing Neutral Currents in W+1 Jet Events at CDF

We report on a search for the non-standard-model process u(c)+g -> t using pp collision data collected by the Collider Detector at Fermilab II detector corresponding to 2.2 fb(-1). The candidate events are classified as signal-like or backgroundlike by an artificial neural network. The observed discriminant distribution yields no evidence for flavor-changing neutral current top-quark production, resulting in an upper limit on the production cross section sigma(u(c)+g -> t)< 1.8 pb at the 95% C.L. Using theoretical predictions we convert the cross section limit to upper limits on flavor-changing neutral current branching ratios: B(t -> u+g)< 3.9x10(-4) and B(t -> c+g)< 5.7x10(-3).