Flavor Changing Leptonic Decays of Heavy Higgs Bosons

TL;DR

This paper investigates flavor-changing leptonic decays of heavy Higgs bosons in specific Two Higgs Doublet Models, motivated by CMS hints of Higgs to mu-tau decay, and finds potentially large decay rates in these models.

Contribution

It analyzes two specific 2HDMs, including a model with flavor-changing neutral processes linked to the weak mixing matrix, predicting large H and A to mu-tau decay rates.

Findings

Decays of H and A to mu-tau can reach up to 60% in the models studied.

Large flavor-changing interactions are possible due to the structure of the models.

The work clarifies the potential for heavy Higgs bosons to exhibit flavor-changing decays.

Abstract

CMS has reported indications (2.4\sigma) of the decay of the Higgs boson into \mu\tau. The simplest explanation for such a decay would be a general Two Higgs Doublet Model (2HDM). In this case, one would expect the heavy neutral Higgs bosons, H and A, to also decay in a similar manner. We study two specific models. The first is the type III 2HDM, and the second is a 2HDM, originally proposed by Branco et al., in which all flavor-changing neutral processes are given by the weak mixing matrix. In the latter model, since mixing between the second and third generations in the lepton sector is large, flavor-changing interactions are large. In this model it is found that the decays of H and A to \mu\tau can be as high as 60 percent. This work has nothing to do with the 750 GeV diphoton resonance.