between observed value and Lattice can be formulated by f Exp D$_{s}$ ≈ f Latt D$_{s}$ ∣ ∣$^{1}$ − m 2 D$_{s}$ m 2 H ± m$_{s}$ m$_{s}$ + m$_{c}$ η 2 s cos φ ℓ s ∣ , (21) V$_{us}$ is known and its uncertainty does not have a significant where we have assumed that V$_{us}$ is known and its uncertainty does not have a significant effect on the decay constant of D$_{s}$ . Taking m$_{c}$ (2GeV) = 1 . 27 GeV, m$_{s}$ (2GeV) = 0 . 104 GeV and m$_{D}$$_{s}$ = 1 . 968 GeV [14], the numerical values of f Exp D$_{s}$ /f Latt D$_{s}$ as a function of η$_{s}$/m$_{H}$ ± and φ ℓ s are plotted in Fig. 3. Owing to the appearance of cos φ ℓ $_{s}$, clearly the sign of H ± contribution could be flipped and the f$_{D}$$_{s}$ puzzle is solved in the general THDM. $_{s}$/m$_{H}$  [GeV$^{−1}$] φ ℓ s [rad] 0.85 0.9 0.95 1 1.05 1.1 1.15 0.2 0.4 0.6 0.8 1 0 0.5 1 1.5 2 2.5 3 FIG. 3: Contour for f$_{D}$$_{s}$ as a function of η$_{s}$/m$_{H}$ ± and new phase φ ℓ $_{s}$, where the values in the figure denote f Exp D$_{s}$ /f Latt D$_{s}$ . According to Eq. (16), the BR for B + → ℓ $^{+}$ν can be straightforward written by with Due to B being a heavy meson, unlike previous cases, we cannot neglect the associated higher order terms. Accordingly, the contour for the influence of H ± on B + → ℓ $^{+}$ν as a function of η$_{b}$/m$_{H}$ ± and φ ℓ b is plotted in Fig. 4, where the values appeared in the figure represent the ratio of B $^{Exp}$( B + → ℓ $^{+}$ν ) / B $^{SM}$( B + → ℓ $^{+}$ν ). We see clearly that the BR for B + → τ $^{+}$ν can be enhanced to the value of world average. In addition to the leptonic decays, we could also study the charged Higgs on semileptonic B decays, such as B → ( P, V ) ℓν . Since the contributions of charged Higgs to light lepton B ( B + → ℓ $^{+}$ν ) = B $^{SM}$( B + → ℓ $^{+}$ν ) | r ℓ B | 2 (22) r ℓ B = 1 − ( η$_{b}$ m$_{B}$ m$_{H}$ ± ) 2 e iφ ℓ b . (23) 9