# Novel probes for electron-muon flavor violation from exotic Higgs decays

## TL;DR

This paper introduces new collider signatures involving Higgs decays to a light pseudoscalar that then decays into an electron-muon pair, offering a promising way to detect lepton flavor violation.

## Contribution

It proposes novel collider signatures for electron-muon flavor violation via exotic Higgs decays involving a light pseudoscalar in the type-III Two-Higgs-doublet-model.

## Key findings

- Proposed signatures lead to stronger constraints on lepton flavor violating couplings than current low-energy measurements.
- Analyzed parameter space where the light pseudoscalar is consistent with existing constraints.
- Collider searches can complement low-energy experiments in probing new physics.

## Abstract

In this paper, we propose two novel signatures of Higgs decays to search for electron-muon flavor violation. These signatures arise from the presence of a light pseudoscalar into which the 125-GeV Higgs boson decays. The pseudoscalar subsequently decays into an electron-muon pair, leading to multilepton final states, which are relatively clean signatures to search for at the LHC. As a benchmark, we consider the type-III Two-Higgs-doublet-model. We analyze both low-energy and collider constraints on the model and identify regions of parameter space where the light pseudoscalar is viable. Our proposed signatures yield stronger constraints on the lepton flavor violating couplings than current low-energy precision measurements. Taken together, our findings suggest that collider-based probes of exotic Higgs decays provide a powerful complement to precision experiments in the quest to uncover new physics.