Branching ratio and CP violation of $B_s\to \pi K$ decays in the perturbative QCD approach

Abstract

In the framework of perturbative QCD approach, we calculate the branching ratio and CP asymmetry for $B_s^0({\bar{B}}_s)\to {\pi }^{\pm }{K}^{\mp }$ and $B_s({\bar{B}}_s)\to {\pi }^0{\bar{K}}^0(K^0)$ decays. Besides the usual factorizable diagrams, both non-factorizable and annihilation type contributions are taken into account. We find that (a) the branching ratio of $B_s^0({\bar{B}}_s)\to {\pi }^{\pm }{K}^{\mp }$ is about $(6-10)\times 10^{-6}$; $Br(B_s({\bar{B}}_s)\to {\pi }^0{\bar{K}}^0(K^0))$ about $(1-3)\times 10^{-7}$; and (b) there are large CP asymmetries in the two processes, which can be tested in the near future LHC-b experiments at CERN and BTeV experiments at Fermilab.

Comments: 19 pages, 5 figures