Leptonic Precision Test of Leptophilic Two-Higgs-Doublet Model

Understand

The type X (lepton-specific) two-Higgs-doublet model at large $\tan\beta$ becomes leptophilic and thus allows a light pseudoscalar $A$ accommodating the observed muon $g-2$ deviation without conflicting with various hadronic constraints.

• On the other hand, it is strongly constrained by leptonic precision observables such as lepton universality test in the neutral and charged currents.
• Treating all the lepton universality data in a consistent way, we show how the current data constrain the parameter space of $m_A$ and $\tan\beta$ for given degenerate masses of heavy Higgs bosons $H$ and $H^\pm$.
• While no overlapping region is found at $1\sigma$, a sizable region is still viable at $2\sigma$ for $H/H^\pm$ masses at around 200$\sim$400 GeV.