Study of B-> phi phi K Decays

Abstract

We report an observation of the decay B^\pm -> ϕϕK^\pm and evidence for B^0 -> ϕϕK^0. These results are based on a 414 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider operating at the Υ(4S) resonance. The branching fractions for these decay modes are measured to be Br(B^{\pm} -> ϕϕK^\pm) = (3.2^{+0.6}_{-0.5} +- 0.3) * 10^{-6} and Br(B^{0} \to ϕϕK^{0}) = (2.3^{+1.0}_{-0.7} +- 0.2) * 10^{-6} for ϕϕinvariant mass below 2.85 GeV/c^2. The corresponding partial rate asymmetry for the charged B mode is measured to be A_{CP}(B^\pm -> ϕϕK^\pm) = 0.01^{+0.19}_{-0.16} +- 0.02. We also study the decays B^\pm -> J/ψK^\pm and B^\pm -> η_c K^\pm, where the J/ψand η_c decay to final states with four charged kaons. We find A_{CP}(B^\pm -> ϕϕK^\pm) with the ϕϕcandidates within the η_c mass region is 0.15^{+0.16}_{-0.17} +- 0.02, consistent with no asymmetry.

6 pages, 3 figures