Branching Ratio and CP Asymmetry of $B_{s} \to \rho(\omega) K $ Decays   in the Perturbative QCD Approach
  In this paper, we calculate the branching ratios and CP-violating asymmetries for $B_{s}\to \rho^\pm K^\mp$, $B_{s}\to\rho^{0}\bar{K}^0 $ and $B_{s}\to\omega\bar{K}^0$ decays in the perturbative QCD (pQCD) factorization approach. The theoretical predictions for the CP averaged branching ratios of the considered decays are: $Br(B_{s}\to\rho^\pm K^\mp)\approx 24.7 \times 10^{-6}$, $Br(B_{s}\to\rho^{0}\bar{K}^0) \approx 1.2 \times 10^{-7}$ and $Br(B_{s} \to\omega\bar{K}^0) \approx 1.7 \times 10^{-7}$; and we also predict very large direct CP-violating asymmetries for the latter two decay modes: $A_{CP}^{dir}(\rho^{\pm} K^{\mp})\approx -12 %$, $A_{CP}^{dir}(\rho^0\bar{K}^0)\approx -92%$, $A_{CP}^{dir}(\omega^0\bar{K}^0)\approx 81%$, $A_{CP}^{mix}(\rho^0\bar{K}^0)\approx -36%$, and $A_{CP}^{mix}(\omega^0\bar{K}^0) \approx -40%$, which can be tested in the forthcoming LHC-b experiments. 
Zhen-jun Xiao, Xin-fen Chen and Dong-qin Guo