Current status of the muon g − 2 interpretations within two-Higgs-doublet models

In this article, we review and update implications of the muon anomalous magnetic moment (muon g−2) anomaly for two-Higgs-doublet models (2HDMs), which are classified according to imposed symmetries and their resulting Yukawa sector. In the minimal setup, the muon g−2 anomaly can be accommodated by the type-X (leptophilic) 2HDM, flavor-aligned 2HDM (FA2HDM), muon-specific 2HDM (μ2HDM), and μτ-flavor-violating 2HDM. We summarize all relevant experimental constraints from high-energy collider experiments and flavor experiments, as well as the theoretical constraints from the perturbative unitarity and vacuum stability bounds, to these 2HDMs in light of the muon g−2 anomaly. We clarify the available parameter spaces of these 2HDMs and investigate how to probe the remaining parameter regions in future experiments. In particular, we find that, due to the updated Bs→μ+μ− measurement, the remaining parameter region of the FA2HDM is almost equivalent to the one of the type-X 2HDM. Furthermore, based on collider simulations, we find that the type-X 2HDM is excluded and the μ2HDM scenario will be covered with the upcoming run 3 data.