Explaining 650 GeV and 95 GeV anomalies in the 2-Higgs doublet model type-I

We propose an interpretation of a rather significant 650[Formula: see text]GeV excess emerged at the Large Hadron Collider (LHC) from CMS Collaboration data in the [Formula: see text] final state, accompanied by further clusters at 125(90–100) GeV in the [Formula: see text] system, within the 2-Higgs Doublet Model Type-I (2HDM-I) in presence of a softly broken [Formula: see text] symmetry. The underlying process that we probe is [Formula: see text]-initiated production of a CP-odd (or pseudoscalar) Higgs boson A, with mass around 650[Formula: see text]GeV, decaying into the Standard Model (SM)-like Higgs state H (decaying into [Formula: see text]) and a Z boson (decaying into [Formula: see text]). We configure this theoretical framework so as to also have in the spectrum a light CP-even (or scalar) Higgs state h with mass around 95[Formula: see text]GeV, which is included for the purpose of simultaneously explaining additional data anomalies seen in the [Formula: see text], [Formula: see text] and [Formula: see text] final states while searching for light Higgs states at the Large Electron-Positron (LEP) collider (the first one) and LHC (the last two). By accounting for both experimental and theoretical constraints, our results show that the 2HDM-I can explain all aforementioned anomalies at a significance level of [Formula: see text].