The size of the branching ratios for the τ→μγ and τ→μγγ decays induced by a lepton flavor violating Higgs
interaction Hτμ is studied in the frame of effective field theories.
The best constraint on the Hτμ vertex, derived from the know
measurement on the muon anomalous magnetic moment, is used to impose the upper
bounds Br(τ→μγ)<2.5×10−10 and Br(τ→μγγ)<2.3×10−12, which are more stringent than current experimental
limits on this class of transitions.Comment: 6 pages, 3 figure