Charged lepton flavor violation in light of Muon $g-2$

Understand

The recent confirmation of the muon $g-2$ anomaly by the Fermilab g-2 experiment may harbinger a new era in $\mu$ and $\tau$ physics.

• In the context of general two Higgs doublet model, the discrepancy can be explained via one-loop exchange of sub-TeV exotic scalar and pseudoscalars, namely $H$ and $A$, that have flavor changing neutral couplings $\rho_{\tau\mu}$ and $\rho_{\mu\tau}$ at $\sim 20$ times the usual tau Yukawa coupling, $\lambda_\tau$.
• Taking $\rho_{\ell\ell^\prime}\sim \lambda_{ \rm min(\ell, \ell^\prime)}$, we show that the above solution to muon $g-2$ then predicts enhanced rates of various charged lepton flavor violating processes, which should be accessible at upcoming experiments.
• We cover muon related processes such as $\mu \to e \gamma$, $\mu \to eee$ and $\mu N \to e N$, and $\tau$ decays $\tau \to \mu \gamma$ and $\tau \to \mu\mu\mu$.