A 96 GeV Higgs Boson in the 2HDMS: $e^+e^-$ collider prospects

TL;DR

This paper interprets a potential 96 GeV Higgs signal observed in experiments as the lightest Higgs in a 2HDMS model, and evaluates its testability at future electron-positron colliders.

Contribution

It provides a viable 2HDMS model explanation for the 96 GeV Higgs signals and analyzes the potential for future collider experiments to test this hypothesis.

Findings

The 2HDMS model can accommodate the 96 GeV Higgs signals within current constraints.

Future $e^+e^-$ colliders like the ILC can effectively probe this model.

The interpretation aligns with experimental excesses and theoretical consistency.

Abstract

The CMS collaboration reported a $\sim 3 \, \sigma$ (local) excess at $96\;$GeV in the search for light Higgs-boson decaying into two photons. This mass coincides with a $\sim 2 \, \sigma$ (local) excess in the $b\bar b$ final state at LEP. We show an interpretation of these possible signals as the lightest Higgs boson in the 2 Higgs Doublet Model with an additional complex Higgs singlet (2HDMS). The interpretation is in agreement with all experimental and theoretical constraints. We concentrate on the 2HDMS type II, which resembles the Higgs and Yukawa structure of the Next-to Minimal Supersymmetric Standard Model. We discuss the experimental prospects for constraining our explanation at future $e^+e^-$ colliders, with concrete analyses based on the ILC prospects.