An extension of two-Higgs-doublet model and the excesses of 750 GeV diphoton, muon g-2 and h → μτ

In this paper we simultaneously explain the excesses of the 750 GeV diphoton, muon g-2 and h→μτh→μτ in an extension of the two-Higgs-doublet model (2HDM) with additional vector-like fermions and a CP-odd scalar singlet (P) which is identified as the 750 GeV resonance. This 750 GeV resonance has a mixing with the CP-odd scalar (A) from a second scalar doublet, which leads to a coupling between P and the SM particles as well as a coupling between A   and the vector-like fermions. Such mixing and couplings are strongly constrained by τ→μγτ→μγ, muon g-2 and the 750 GeV diphoton data. We scan over the parameter space and find that such an extension can simultaneously account for the observed excesses of 750 GeV diphoton, muon g-2 and h→μτh→μτ. The 750 GeV resonance decays in exotic modes, such as P→hAP→hA, P→HZP→HZ, P→HAP→HA and P→W±H∓P→W±H∓, and its width can be dozens of GeV and is sensitive to the mixing angle.