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

TL;DR

This paper explores the possibility of explaining the CMS hint of Higgs decay to muon and tau within a minimal flavor violation framework extended by right-handed neutrinos and dimension-six operators, considering experimental constraints and future tests.

Contribution

It introduces a model combining minimal flavor violation with right-handed neutrinos and dimension-six operators to account for the $h o\mu au$ decay signal.

Findings

The $h o\mu au$ signal can be explained with specific neutrino-Higgs couplings.

Constraints from $\mu o e\gamma$ and $\mu o e$ conversion are analyzed.

Future experiments can further test the lepton-flavor-violating Higgs interactions.

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.