$R(D^{(\ast )})$ and $\mathcal{B}r(B\to \tau {\nu }_{\tau })$ in a Flipped/Lepton-Specific 2HDM with anomalously enhanced charged Higgs coupling to $\tau$/b

Babar, Belle and recently LHCb has reported an excess in the measurements of $R(D^{\ast })$, $R(D)$ and $\mathcal{B}r(B\to \tau {\nu }_{\tau })$ than expected from SM, a possible signature of lepton flavor universality violating NP. In this work we analyze the phenomenological implications for these decay modes in a Flipped/Lepton-Specific 2HDM with anomalously enhanced Yukawa coupling of $H^{\pm }$ to $\tau$/b. When experimental and theoretical errors are added in quadrature, we conclude that this phenomenological extension of SM can give results in agreement within 1$\sigma$ deviation for the combination of $R(D^{(\ast )})$ and $\mathcal{B}r(B\to \tau {\nu }_{\tau })$ compare to about 4$\sigma$ deviation from SM from the latest combined[Babar,Belle,LHCb] experimental data for these observables.