Higgs Decay $h\to \mu \tau$ with Minimal Flavor Violation

Abstract

We consider the tentative indication of flavor-violating Higgs boson decay $h\to \mu \tau$ recently reported in the CMS experiment within the framework of minimal flavor violation. Specifically, we adopt the standard model extended with the seesaw mechanism involving right-handed neutrinos plus effective dimension-six operators satisfying the minimal flavor violation principle in the lepton sector. We find that it is possible to accommodate the CMS $h\to \mu \tau$ signal interpretation provided that the right-handed neutrinos couple to the Higgs boson in some nontrivial way. We take into account empirical constraints from other lepton-flavor-violating processes and discuss how future searches for the $\mu \to e\gamma$ decay and $\mu \to e$ conversion in nuclei may further probe the lepton-flavor-violating Higgs couplings.

Comments: 15 pages, no figures, minor errors corrected, references added, matches publication