Observation of B0s → χc1 ϕ Decay and Study of B0 → χc1,2 K⁎0 Decays

The first observation of the decay B0s → χc1 ϕ and a study of B0 → χc1,2 K⁎0 decays are presented. The analysis is performed using a dataset, corresponding to an integrated luminosity of 1.0 fb^−1, collected by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. The following ratios of branching fractions are measured: B(B0s → χc1 ϕ) / B(B0s → J/ψ ϕ) = (18.9 ± 1.8(stat) ± 1.3(syst) ± 0.8(B)) x 10^−2, B(B0 → χc1 K⁎0) / B(B0 → J/ψ K⁎0) = (19.8 ± 1.1(stat) ± 1.2(syst) ± 0.9(B)) x 10^−2, B(B0 → χc2 K⁎0) / B(B0 → χc1 K⁎0) = (17.1 ± 5.0(stat) ± 1.7(syst) ± 1.1(B)) x 10^−2, where the third uncertainty is due to the limited knowledge of the branching fractions of χc → J/ψ γ modes.