Higgs mediated lepton flavor violating tau decays $\tau \to \mu \gamma$ and $\tau \to \mu \gamma \gamma$ in effective theories

TL;DR

This paper investigates the potential rates of lepton flavor violating tau decays mediated by Higgs interactions within effective theories, establishing upper bounds that surpass current experimental limits.

Contribution

It provides new upper bounds on tau decay branching ratios induced by Higgs-mediated lepton flavor violation, based on constraints from the muon anomalous magnetic moment.

Findings

Derived upper bounds on $Br( au o  )$ and $Br( au o   )$.

Bounds are more stringent than existing experimental limits.

Uses effective field theory and muon g-2 constraints.

Abstract

The size of the branching ratios for the $\tau \to \mu \gamma$ and $\tau \to \mu \gamma \gamma$ decays induced by a lepton flavor violating Higgs interaction $H\tau \mu$ is studied in the frame of effective field theories. The best constraint on the $H\tau \mu$ vertex, derived from the know measurement on the muon anomalous magnetic moment, is used to impose the upper bounds $Br(\tau \to \mu \gamma)<2.5\times 10^{-10}$ and $Br(\tau \to \mu \gamma \gamma)<2.3\times 10^{-12}$, which are more stringent than current experimental limits on this class of transitions.