Exploring Potential Higgs Resonances at 650 GeV and 95 GeV in the 2HDM Type III

TL;DR

This paper investigates anomalies at 650 GeV and 95 GeV in collider data, proposing a 2HDM Type III framework where specific Higgs bosons decay into observed final states, potentially indicating new physics beyond the Standard Model.

Contribution

It introduces a novel 2HDM Type III scenario that simultaneously explains the 650 GeV and 95 GeV excesses observed in collider experiments.

Findings

Both signals can be fitted simultaneously at 2.5σ significance.

The model provides a consistent BSM explanation for the observed anomalies.

Proposes specific Higgs decay channels matching experimental excesses.

Abstract

Recent searches by the CMS collaboration at the Large Hadron Collider (LHC) in the `diphoton plus $b\bar{b}$ final state' have revealed an excess near 650 GeV, which might indicate the presence of a (broad) heavy resonance decaying into a Standard Model (SM) Higgs boson and an additional particle. At the same time, both ATLAS and CMS as well as all experiments at the Large Electron-Position (LEP) collider have reported excesses consistent with a light Higgs boson channel around 95 GeV, suggesting a potential connection between these two signals. In this study, we investigate these anomalies within the context of the CP-conserving 2-Higgs-Doublet Model (2HDM) Type~III. In our proposed scenario, a heavy CP-odd Higgs boson $A$ with a mass near 650 GeV decays into a SM-like Higgs boson $H$ and a $Z$ boson, with the $H$ boson subsequently decaying into diphotons and the $Z$ boson decaying into $b\bar{b}$ pairs. To explain the excess around 95 GeV, we independently select the mass of the light CP-even Higgs boson of the model $h$ to be around this value. This configuration allows for a consistent explanation of both the high- and low-mass excesses observed in the experiments. Through a detailed analysis, we demonstrate that these two signals can be fitted simultaneously at the 2.5$\sigma$ significance level, offering a promising solution to the observed anomalies and potentially hinting at new physics Beyond the Standard Model (BSM).