Implications of the muon anomalous magnetic moment and Higgs-mediated flavor changing neutral currents

Abstract In the light of the recent measurement of the muon anomalous magnetic moment a μ by the Muon ( g −2) Collaboration, we examine the contribution to a μ from the exchange of flavor changing scalars. Assuming that the heavier generations have larger flavor changing couplings, we obtain a bound on the μ – τ Yukawa coupling for a given scalar mass. Constraints on other individual flavor changing/conserving couplings are also obtained from the lepton flavor violating decays of the muon and tau leptons, and bounds on the branching ratio of τ →3 e , μ →3 e and τ → eμe processes are predicted. In addition, we study the implications of the lepton flavor violating pair production at e + e − colliders.