SSP2012 - 5th International Symposium on Symmetries in Subatomic Physics

Many extensions of the standard model contain an additional $U(1)^\prime$ gauge group with an associated $Z^\prime$ gauge boson. In some of those constructions the $U(1)^\prime$ charges are generation dependent and therefore introduce tree-level flavor changing neutral currents mediated by the $Z^\prime$. We discuss the phenomenology of these FCNC couplings for meson decays and possible LHC implications. We discuss a class of models with a down-quark mass matrix of the Georgi-Jarlskog type which naturally satisfies the current experimental constraints on FCNC.