Implication of $b \to c\tau\nu$ flavor anomalies on $B_s\rightarrow {D_s^*}\tau\nu$ decay observables

Abstract

The experimental predictions of $R_D$, $R_{D^*}$, $R_{J/\psi}$, $P_\tau^{D^*}$ and $F_L^{D^*}$ in $B$ decays mediated via $b\,\to\, c\, l\,\nu$ quark level transition deviate significantly from the standard model expectations. The current world average of the ratio of branching ratios $R_D$ and $R_{D^*}$ in $B\,\to\, D^{(*)}\, l\,\nu$ ($l\in e,\tau$) show $1.4\sigma$ and $2.5\sigma$ deviation from the SM expectations. Similarly, the $\tau$ polarization fraction $P_{\tau}^{D^*}$ and the longitudinal polarization fraction of the $D^*$ meson $F_L^{D^*}$ in $B\,\to\, D^*\,\tau\,\nu$ are found to deviate from the standard model expectations at $1.6\sigma$ and $1.5\sigma$ level, respectively. In addition, the ratio of branching ratio $R_{J/\psi}$ in $B_c\,\to\,{J/\psi}\, l\,\nu$ deviates from the standard model prediction at $2\sigma$ level. In this regard, we study the implication of $R_D$, $R_{D^*}$, $R_{J/\psi}$, $P_\tau^{D^*}$, and $F_L^{D^*}$ anomalies on $B_s\,\to\, {D^*_s}\,\tau\,\nu$ decay observables in a model independent effective field theory formalism. We give predictions of several physical observables in the standard model and in the presence of various $1D$ and $2D$ new physics scenarios.