Higgs-flavon mixing and h -> mu tau

Abstract

ATLAS and CMS have reported an excess in the flavor violating decay of the Higgs boson, h -> mu tau. We show that this result can be accommodated through a mixing of the Higgs with a flavon, the field responsible for generating the Yukawa matrices in the lepton sector. We employ a version of the Froggatt-Nielsen mechanism at the electroweak scale, with only the leptons and the flavon transforming non-trivially under the corresponding symmetry group. Non-observation of charged lepton flavor violation (LFV) in other processes imposes important constraints on the model, which we find to be satisfied in substantial regions of parameter space.