Search for the decay B0 → ϕϕ

A bstract A search for the decay B 0 → ϕϕ is made using pp collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb − 1 . No significant signal is observed, and an upper limit on the branching fraction of 1 . 3 (1 . 4) × 10 − 8 at 90 (95)% confidence level is set. This result supersedes the previous LHCb study and improves the upper limit by a factor of two.