Measurement of branching fraction and search for CP violation in B →φφK.

Abstract

We report the measurement of branching fractions and CP-violation asymmetries in B → ϕϕK decays based on a 711 fb−1 data sample containing 772 × 106 BB¯ events. The data were recorded at the ϒð4SÞ resonance with the Belle detector at the KEKB asymmetric-energy eþe− collider. For Bþ → ϕϕKþ, the branching fraction and CP-violation asymmetry measured below the ηc threshold (mϕϕ < 2.85 GeV=c2) are ½3.43þ0.48 −0.46 ðstatÞ 0.22ðsystÞ × 10−6 and −0.02 0.11ðstatÞ 0.01ðsystÞ, respectively. Similarly, the branching fraction obtained for B0 → ϕϕK0 below the ηc threshold is ½3.02þ0.75 −0.66 ðstatÞ 0.20ðsystÞ×10−6. We also measure the CP-violation asymmetry for Bþ → ϕϕKþ within the ηc region (mϕϕ ∈ ½2.94; 3.02 GeV=c2) to be þ0.12 0.12ðstatÞ 0.01ðsystÞ.