Branching ratio and CP asymmetry of Bs→π+π- decays in the perturbative QCD approach -: art. no. 034009

In this paper, we calculate the decay rate and CP asymmetry of the B-s-->pi(+)pi(-) decay in the perturbative QCD approach with Sudakov resummation. Since none of the quarks in final states is the same as those of the initial B-s meson, this decay can occur only via annihilation diagrams in the standard model. Besides the current-current operators, the contributions from the QCD and electroweak penguin operators are also taken into account. We find that (a) the branching ratio is about 4x10(-7); (b) the penguin diagrams dominate the total contribution; and (c) the direct CP asymmetry is small in size: no more than 3%; but the mixing-induced CP asymmetry can be as large as 10% testable in the near future LHC-b experiments.