Implications for new physics from a novel puzzle in $\bar{B}_{(s)}^0 \to D^{(\ast)+}_{(s)} \lbrace \pi^-, K^- \rbrace$ decays

Abstract

Recently, the standard model predictions for the $B$-meson hadronic decays, $\bar{B}^0 \to D^{(\ast)+}K^-$ and $\bar{B}^0_s \to D^{(\ast)+}_s \pi^-$, have been updated based on the QCD factorization approach. This improvement sheds light on a novel puzzle in the $B$-meson hadronic decays: there are mild but universal tensions between data and the predicted branching ratios. Assuming the higher-order QCD corrections are not huge enough to solve the tension, we examine several new physics interpretations of this puzzle. We find that the tension can be partially explained by a left-handed $W^\prime$ model, which can be compatible with other flavor observables and collider bounds.