Dielectron and Diphoton channels in 2HDM

TL;DR

This paper explores how two-Higgs-Doublet-Models (2HDM) can produce measurable dielectron and diphoton decay channels, unlike most Standard Model extensions, and confirms their consistency with low-energy experimental constraints.

Contribution

It identifies parameter regions in 2HDM where dielectron and diphoton decays are significant, providing a novel exception to previous decay suppression results.

Findings

2HDM can produce observable dielectron and diphoton decays.

The model remains consistent with lepton magnetic moments and flavor-violating decay constraints.

Abstract

It was observed recently by Randall and Wise that, any particle in the Standard Model cannot decay to $e^+e^-$ and $\gamma \gamma$ final states with comparably measurable branching ratios. This is also true for most extensions of the Standard Model, with the Randall-Sundrum model as an outstanding exception. In this paper, we show that two-Higgs-Doublet-Models (2HDM) yield another possible exception if certain parameters are properly chosen. In addition, we have checked that this model survives the tests of low energy processes, including the anomalous magnetic moment and electric dipole moment of leptons, lepton-flavor-violating decays $\mu^- \to e^- \gamma$ and $e^- e^+ e^-$.