  A search for flavor-changing neutral currents in top-quark decays t to Zq is
performed in events produced from the decay chain t t-bar to Zq + Wb, where
both vector bosons decay leptonically, producing a final state with three
leptons (electrons or muons). A data set collected with the CMS detector at the
LHC is used, corresponding to an integrated luminosity of 19.7 inverse
femtobarns of proton-proton collisions at a center-of-mass energy of 8 TeV. No
excess is seen in the observed number of events relative to the standard model
prediction; thus, no evidence for flavor-changing neutral currents in top-quark
decays is found. A combination with a previous search at 7 TeV excludes a t to
Zq branching fraction greater than 0.05% at the 95% confidence level.
