A search for the rare decays Bs0++ and B0++ is performed in a data set corresponding to an integrated luminosity of 3.0 fb1 collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0++ and the first evidence of the decay B0++ are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0++)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))×108 and B(B0++)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×108, where the third uncertainty is due to the branching fraction of the decay B0J/(+)K(892)0(K+), used as a normalisation.
