Evidence for B → φφK

We report evidence for the decay mode B → ΦΦK based on an analysis of 78 fb - 1 of data collected with the Belle detector at KEKB. This is the first example of a b → sssss transition. The branching fraction for this decayis measured to be B(B ′ → ΦΦK ′ ) = (2.6 + 1 . 1 -0.9 ′ 0.3) × 10 - 6 for a ΦΦ invariant mass below 2.85 GeV/c 2 . Results for other related charmonium decay modes are also reported.