NP parameter space at $95\%$ (blue) CL obtained from the measured values of $R_D$, $R_{D^{\ast}}$, and $R_{J/\Psi}$. We also show the allowed ranges in $(R_D,\,P_{\tau}^D)$, $(R_{D^{\ast}},\,P_{\tau}^{D^{\ast}})$, and $(R_{J/\Psi},\,P_{\tau}^{J/\Psi})$ for each of these NP scenarios. It is clear that with all these NP couplings, the allowed ranges in $R_D$, $R_{D^{\ast}}$,$R_{J/\Psi}$, and $P_{\tau}^{D^{\ast}}$ at $95\%$ (blue) CL do overlap with the experimentally allowed values within $1\sigma$. It should, however, be mentioned that with $(\widetilde{V}_R,\,\widetilde{T}_L)$ NP couplings, the value of $P_{\tau}^{D}$ can be negative depending on the value of the NP couplings. Similarly, we do not see much variation of $P_{\tau}^{D}$ with $(V_R,\,\widetilde{T}_L)$ NP couplings. Measurement of $P_{\tau}^{D}$ and $P_{\tau}^{J/\Psi}$ in future will also play a crucial role.

![The allowed NP parameter space (leftmost panels) at $95\%$ (blue) CL from $R_D$, $R_{D^{\ast}}$, and $R_{J/\Psi}$ measurements. The corresponding allowed ranges in $(R_D,\,P_{\tau}^D)$, $(R_{D^{\ast}},\,P_{\tau}^{D^{\ast}})$, and $(R_{J/\Psi},\,P_{\tau}^{J/\Psi})$ are shown with blue dots. The experimental $1\sigma$ range of $R_D$, $R_{D^{\ast}}$, and $R_{J/\Psi}$ are shown with light red bands. The horizintal line in the second panel represents the central value of $P_{\tau}^{D^{\ast}}$ reported by BELLE.[]{data-label="NP2"}](vrtlt_1sig_95cl.png "fig:"){width="4.3cm" height="4.3cm"} ![The allowed NP parameter space (leftmost panels) at $95\%$ (blue) CL from $R_D$, $R_{D^{\ast}}$, and $R_{J/\Psi}$ measurements. The corresponding allowed ranges 