Muon g$-$2 in two-Higgs-doublet models

Understand

Updating various theoretical and experimental constraints on the four different types of two-Higgs-doublet models (2HDMs), we find that only the ``lepton-specific" (or ``type X") 2HDM can explain the present muon g$-$2 anomaly in the parameter region of large $\tan\beta$, a light CP-odd boson, and heavier CP-even and charged bosons which are almost degenerate.

• The severe constraints on the models come mainly from the consideration of vacuum stability and perturbativity, the electroweak precision data, the $b$-quark observables like $B_S \to \mu\mu$, the precision measurements of the lepton universality as well as the 125 GeV boson property observed at the LHC.