Lepton Flavour Violating Higgs Decays in the (SUSY) Inverse Seesaw

TL;DR

This paper investigates lepton flavour violating Higgs decays within inverse seesaw models, predicting potentially observable branching ratios that could be detected in future collider experiments and explain current experimental hints.

Contribution

It provides new predictions for LFV Higgs decay rates in inverse seesaw and supersymmetric inverse seesaw models, highlighting their experimental testability.

Findings

Branching ratios up to 10^{-5} for h→τμ and h→τe in inverse seesaw.

Supersymmetric contributions can increase h→τμ branching ratio to 1%.

Predictions are within reach of future collider experiments.

Abstract

The observation of charged lepton flavour violation would be a smoking gun for new physics and could help in pinpointing the mechanism at the origin of neutrino masses and mixing. We present here our recent studies of lepton flavour violating Higgs decays in the inverse seesaw and its supersymmetric embedding, two examples of low-scale seesaw mechanisms. We predict branching ratios as large as $10^{-5}$ for the decays $h\rightarrow \tau \mu$ and $h \rightarrow \tau e$ in the inverse seesaw, which can be probed in future colliders. Supersymmetric contributions can enhance the branching ratio of $h\rightarrow \tau \mu$ up to $1\%$, making it large enough to explain the small excess observed by ATLAS and CMS.