Abstract
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-1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by BC≡B(b→CX)×B(C) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of ϕ mesons, ratios RC2C1≡BC1/BC2 are determined as Rηc(1S)χc0=0.147±0.023±0.011, Rηc(1S)χc1=0.073±0.016±0.006, Rηc(1S)χc2=0.081±0.013±0.005, Rχc0χc1=0.50±0.11±0.01, Rχc0χc2=0.56±0.10±0.01 and Rηc(1S)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 c 2(2 P) states are obtained as Rχc1X(3872)<0.34, Rχc0X(3915)<0.12 and Rχc2χc2(2P)<0.16. Differential cross-sections as a function of transverse momentum are measured for the ηc(1 S) and χc states. The branching fraction of the decay Bs0 is measured for the first time, B(Bs0)=(2.15±0.54±0.28±0.21B)×10-6. Here the third uncertainty is due to the branching fraction of the decay Bs0, 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(1 S) decays to ϕϕ and pp¯ as B(ηc(1S))/B(ηc(1S)→pp¯)=1.79±0.14±0.32.
Original language | English |
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Article number | 609 |
Journal | European Physical Journal C |
Volume | 77 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1 Sept 2017 |
Funding
Acknowledgements We would like to thank Emi Kou for motivating the studies of charmonium production in LHCb using hadronic final states and the useful discussions regarding charmonium production mechanisms. We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (The Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MinES and FASO (Russia); MinECo (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (UK); NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (The Netherlands), PIC (Spain), GridPP (UK), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany), EPLANET, Marie Skłodowska-Curie Actions and ERC (European Union), Conseil Général de Haute-Savoie, Labex ENIGMASS and OCEVU, Région Auvergne (France), RFBR and Yandex LLC (Russia), GVA, XuntaGal and GENCAT (Spain), Herchel Smith Fund, The Royal Society, Royal Commission for the Exhibition of 1851 and the Leverhulme Trust (UK).
Funders | Funder number |
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Not added | 1681016 |
AvH Foundation | |
CNRS/IN2P3 | |
EPLANET | |
FASO | |
Herchel Smith Fund | |
Labex ENIGMASS | |
MinES | |
OCEVU | |
Région Auvergne | |
Yandex LLC | |
National Science Foundation | |
School of Energy Resources, University of Wyoming | |
H2020 Marie Skłodowska-Curie Actions | |
CERN | |
Science and Technology Facilities Council | ST/L001152/1, ST/N000250/1, ST/H006737/1, ST/N000331/1, GRIDPP, LHCb Upgrades, 1707993, ST/J004332/1, 1641747, ST/M003140/1, ST/K003410/1, 1708182, ST/G005974/1, LHCb |
Leverhulme Trust | |
Royal Society | |
Royal Commission for the Exhibition of 1851 | |
European Commission | |
European Research Council | |
Deutsche Forschungsgemeinschaft | |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | 166208 |
National Natural Science Foundation of China | |
Russian Foundation for Basic Research | |
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior | |
Bundesministerium für Bildung und Forschung | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Generalitat Valenciana | |
Conselho Nacional de Desenvolvimento Científico e Tecnológico | |
Ministry of Science and Technology | |
Instituto Nazionale di Fisica Nucleare | |
Narodowe Centrum Nauki | |
Ministerstwo Nauki i Szkolnictwa Wyższego | |
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro | |
National Academy of Sciences of Ukraine | |
Financiadora de Estudos e Projetos | |
Conseil Général de l'Aisne |