A search for the rare decay B0 → J/ φ is performed 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 of the decay is observed and an upper limit of 1.1 × 10-7 at 90% confidence level is set on the branching fraction.
