Large CP violation in B_s meson mixing with EDM constraint in supersymmetry

Motivated by the recent measurement of the like-sign dimuon charge asymmetry, we investigate anomalous CP violation in the B_s- B̄_s mixing within the supersymmetry. We show that when gluino diagrams dominate supersymmetry contributions, it is very difficult to realize a large B_s - B̄_s mixing phase under the constraint from electric dipole moments barring cancellations. This constraint can be relaxed by supposing superparticles decoupled. We find that it is possible to achieve the large CP asymmetry, and the branching ratio of B_s → μ⁺μ^- becomes sizable.