Rare Decays of B and D Hadrons at CDF
  Decays that are highly suppressed in the standard model are excellent places to search for effects of new physics. Decays mediated by flavor-changing neutral currents are forbidden at tree level in the SM, and are often further suppressed by helicity and the Glashow-Iliopoulos-Maiani mechanism. Exclusive final states with charged lepton pairs are a particular strength of the CDF experiment due to the large bottom and charm production cross section and the ability to efficiently separate signal from background. CDF has searched for and set the world's best limits on the rare flavor-changing neutral current decays B^0_(s) rightarrow mu^+mu^-, B^0_(s) rightarrow e^+ e^-, and D^0 rightarrow mu^+mu^-, and the lepton flavor violating decay B^0_(s) rightarrow e^+/- \mu^-/+. 
R.F. Harr (for the CDF collaboration)