The CKM suppressed $B(B_s) \to \bar D_{(s)}P,\bar D_{(s)}V,\bar D_{(s)}^*P, \bar D_{(s)}^*V$ decays in perturbative QCD approach

Understand

Although the two-body charmed decays $B_{(s)} \to \bar D_{(s)}^{(*)}P$ and $\bar D_{(s)}^{(*)}V$, where $P$($V$) denotes a light pseudoscalar(vector) meson, are CKM suppressed comparing with the $B_{(s)} \to D_{(s)}^{(*)}P$ and $ D_{(s)}^{(*)}V$ decays, they are important in the CKM angle $\gamma=\phi_3$ extraction method.

• We investigated these decays in the perturbative QCD approach to the leading order of $m_D/m_B$ and $\Lambda_{\rm{QCD}}/m_D$ expansion.
• We find that the nonfactorizable emission diagrams and the annihilation diagrams are not negligible in many of these channels.
• The numerical results show that most channels have branching ratios with an order of $10^{-6}$ or $10^{-7}$.