Study of charmonium production in b-hadron decays and first evidence for the decay B⁰_s → φφφ

Using decays to φ-meson pairs, the inclusive production of charmonium states in b-hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by BC ≡ B(b → C X) × B(C → φφ) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of φ mesons, ratios RC1 C2 ≡ BC1 /BC2 are determined as Rχc0 ηc(1S) = 0.147 ± 0.023 ± 0.011, Rχc1 ηc(1S) = 0.073 ± 0.016 ± 0.006, Rχc2 ηc(1S) = 0.081 ± 0.013 ± 0.005, Rχc1 χc0 = 0.50 ± 0.11 ± 0.01, Rχc2 χc0 = 0.56 ± 0.10 ± 0.01 and Rηc(2S) ηc(1S) = 0.040 ± 0.011 ± 0.004. Here and below the first uncertainties are statistical and the second systematic. Upper limits at 90% confidence level for the inclusive production of X(3872), X(3915) and χc2(2P) states are obtained as RX(3872) χc1 < 0.34, RX(3915) χc0 < 0.12 and Rχc2(2P) χc2 < 0.16. Differential cross-sections as a function of transverse momentum are measured for the ηc(1S) and χc states. The branching fraction of the decay B0 s → φφφ is measured for the first time, B(B0 s → φφφ) = (2.15±0.54± 0.28±0.21B)×10−6. Here the third uncertainty is due to the branching fraction of the decay B0 s → φφ, which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse φ polarization is observed. The measurements allow the determination of the ratio of the branching fractions for the ηc(1S) decays to φφ and p p as B(ηc(1S)→ φφ)/B(ηc(1S)→ p p) = 1.79 ± 0.14 ± 0.32.