Study of charmonium production in b-hadron decays and first evidence for the decay B[subscript 0][subscript s] →ϕϕϕ
Author(s)
Boettcher, Thomas Julian; Ilten, Philip J; Williams, Michael
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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 3.0fb[superscript -1], collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by BC≡B(b→CX)×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 R[superscript C1][subscript C1]≡B[subscript C1]/B[subscript C2] are determined as R[subscript ηc(1S)][superscript χc0] = 0.147±0.023±0.011, R[subscript ηc(1S)][superscript χc1] = 0.073±0.016±0.006, R[subscript ηc(1S)][superscript χc2] = 0.081±0.013±0.005, R[subscript χc0][superscript χc1] = 0.50±0.11±0.01, R[subscript χc0][superscript χc2] = 0.56±0.10±0.01 and R[subscript ηc(1S)][superscript ηc(2S)] = 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 χ[subscript c2](2P) states are obtained as R[subscript χc1][superscript X(3872)] < 0.34, R[subscript χc0][superscript X(3915)] < 0.12 and R[subscript χc2][superscript χc2](2P) < 0.16 . Differential cross-sections as a function of transverse momentum are measured for the η[subscript c](1S) and χ[subscript c] states. The branching fraction of the decay B[subscript s][superscript 0] → ϕϕϕ is measured for the first time, B(B[subscript s][superscript 0] → ϕϕϕ)=(2.15±0.54±0.28±0.21B) × 10[superscript -6]. Here the third uncertainty is due to the branching fraction of the decay B[subscript s][superscript 0] → 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[bar over p] as B(η[subscript c](1S) → ϕϕ)/B(η[subscript c](1S) → p[bar over p]) = 1.79±0.14±0.32 .
Date issued
2017-09Department
Massachusetts Institute of Technology. Department of PhysicsJournal
The European Physical Journal C
Publisher
Springer/Società Italiana di Fisica
Citation
LHCb Collaboration, et al. “Study of Charmonium Production in b-Hadron Decays and First Evidence for the Decay B[superscript 0][subscript s] → ϕ ϕ ϕ.” The European Physical Journal C, vol. 77, no. 9, Sept. 2017. © 2017 The Authors
Version: Final published version
ISSN
1434-6044
1434-6052