The Anomalous Magnetic Moment of the Muon and Higgs-Mediated Flavor   Changing Neutral Currents
  In the two-Higgs doublet extension of the standard model, flavor-changing neutral couplings arise naturally. In the lepton sector, the largest such coupling is expected to be $\mu-\tau-\phi#. We consider the effects of this coupling on the anomalous magnetic moment of the muon. The resulting bound on the coupling, unlike previous bounds, is independent of the value of other unknown couplings. It will be significantly improved by the upcoming E821 experiment at Brookhaven National Lab. 
Shuquan Nie and Marc Sher