The Electron/Muon Specific Two Higgs Doublet Model at e+ e- Colliders

TL;DR

This paper explores the phenomenology of an electron/muon specific two Higgs doublet model at e+ e- colliders, highlighting potential signals and experimental bounds for Higgs bosons in the 150-210 GeV range.

Contribution

It analyzes the collider phenomenology of the KOY two Higgs doublet model at electron-positron colliders, focusing on Higgs-mediated muon pair production and experimental constraints.

Findings

LEP-200 bounds surpass LHC constraints for 150-210 GeV Higgs masses.

Muon pair production via s-channel Higgs exchange is feasible at the ILC with energy scanning.

The model predicts enhanced Higgs couplings to electrons and muons, enabling unique collider signatures.

Abstract

Recently, Kajiyama, Okada and Yagyu (KOY) proposed an electron/muon specific two Higgs doublet model. In this model, an S3 symmetry suppresses flavor changing neutral currents instead of a Z2 symmetry. In the "Type I" version of the model, the heavy Higgs bosons have a greatly enhanced coupling to electrons and muons. KOY studied the phenomenology of the heavy Higgs bosons at the LHC. In this paper, the phenomenology at electron-positron colliders is studied. For the heavy Higgs mass range between 150 and 210 GeV, bounds from LEP-200 are stronger than those from the LHC. The model allows for the interesting possibility that muon pair production at the ILC can be mediated by s-channel Higgs exchange. This requires an energy scan. The scanning rate and necessary resolution are discussed.