New physics contributions to $\bar{B}^0_{(s)}→ D^{(∗)}_{(s)}K/π$

Recently, the standard model predictions for the $B$-meson hadronic decays,
$\bar{B}^0→D^{(∗)+}K^−$ and $\bar{B}^0_s→D^{(∗)+}_sπ^−$, have been updated based on the QCD factorization approach.
This improvement sheds light on a novel puzzle of $4−5σ$ in the $B$-meson hadronic decays: there are universal tensions between data and the predicted branching ratios.
Assuming the higher-order QCD corrections are not huge enough to solve the tension, several new physics interpretations of this puzzle is examined.
It is found that the tension can be partially explained by a left-handed $W′$ model which can be compatible with other flavor observables and collider bounds.