Investigating ${R}_{D}$ and ${R}_{{D}^{\ast }}$ anomalies in a left–right model with an inverse seesaw

We investigate ${R}_{D}$ and ${R}_{{D}^{\ast }}$ anomalies in a low scale left–right symmetric model based on $SU{\left(3\right)}_{C}×SU{\left(2\right)}_{L}×SU{\left(2\right)}_{R}×U{\left(1\right)}_{B-L}$ with a simplified Higgs sector consisting of only one bidoublet and one $SU{\left(2\right)}_{R}$ doublet. The Wilson coefficients relevant to the transition $b\to c\tau \nu $ are derived by integrating out the charged Higgs ${H}^{±}$ boson, which gives the dominant contributions. We emphasize that the charged Higgs effects, with the complex right-handed quark mixing matrix, can account for both ${R}_{D}$ and ${R}_{{D}^{\ast }}$ anomalies simultaneously, while adhering to a set of significant constraints including, for instance, $\text{BR}\left({B}_{c}^{-}\to {\tau }^{-}{\overline{\nu }}_{\tau }\right)$ and ${B}_{s\left(d\right)}-{\overline{B}}_{s\left(d\right)}$ mixing. In relation to this, we show that the predicted values of the ${D}^{\ast }$ , $\tau $ longitudinal polarizations and ${P}_{\tau }\left(D\right)$ can be affected for the set of the parameters of the model resolving the ${R}_{D,{D}^{\ast }}$ anomalies.