Study of $B_s\to \pi \rho$ decays in the perturbative QCD approach

Abstract

In this note, we calculate the branching ratio and CP asymmetry parameters of $B_s\to \pi \rho$ in the framework of perturbative QCD approach based on $k_T$ factorization. This decay can occur only via annihilation diagrams in the Standard Model. We find that (a)the charge averaged $Br(B_s\to {\pi }^{+}{\rho }^{-}+{\pi }^{-}{\rho }^{+})$ is about $(9-12)\times 10^{-7}$; $Br(B_s\to {\pi }^0{\rho }^0)\simeq 4\times 10^{-7}$; and (b) there are sizable CP asymmetries in the processes, which can be tested in the near future Large Hadron Collider beauty experiments (LHC-b) at CERN or BTeV experiments at Fermilab.

Comments: 6 pages, 3 figures