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Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/186477
Study of charmonium production in b -hadron decays and first evidence for the decay Bs0
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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 3.0 { fb}^{-1} , collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by B_C ≡ 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^{C_1}_{C_2}≡ B_{C_1} / B_{C_2} are determined as R^{χ_{c} 0}_{{η _{{c}}} (1S)} = 0.147 ± 0.023 ± 0.011, R^{χ_{c} 1}_{{η _{{c}}} (1S)} = 0.073 ± 0.016 ± 0.006, R^{χ_{c} 2}_{η _{c} (1S)} = 0.081 ± 0.013 ± 0.005, R^{χ_{c} 1}_{χ_{c} 0} = 0.50 ± 0.11 ± 0.01, R^{χ_{c} 2}_{χ_{c} 0} = 0.56 ± 0.10 ± 0.01 and R^{{η _{{c}}} (2S)}_{{η _{{c}}} (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 χ_{c} 2} (2P) states are obtained as R^{X(3872)}_{χ_{c} 1} < 0.34, R^{X(3915)}_{χ_{c} 0} < 0.12 and R^{χ_{c} 2} (2P)}_{χ_{c} 2} < 0.16. Differential cross-sections as a function of transverse momentum are measured for the {η _{{c}}} (1S) and χ _c states. The branching fraction of the decay B ^0_{s} → φ φ φ is measured for the first time, B ( B^0_{s} → φφφ) = (2.15 ± 0.54 ± 0.28 ± 0.21_{B}) × 10^{-6}. Here the third uncertainty is due to the branching fraction of the decay B^0_{s} → φ φ , 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 {η _{{c}}} (1S) decays to φ φ and p {\overline{p}} as B( η_{c} (1S)→ φφ)/B(η_{c} (1S)→ p {\overline{p}} ) = 1.79 ± 0.14± 0.32.
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CAMBONI, Alessandro, COQUEREAU, S., FERNANDEZ, G., GARRIDO BELTRÁN, Lluís, GASCON, D., GRACIANI DIAZ, Riardo, GRAUGÉS POUS, Eugeni, MARIN BENITO, Carla, PICATOSTE OLLOQUI, Eduardo, RIVES MOLINA, Vicente josé, SANCHEZ GONZALO, D., ALFONSO ALBERO, Alejandro, CALVO GOMEZ, M., GIRONELLA GIRONELL, P., VAZQUEZ GOMEZ, R., LHCb Collaboration. Study of charmonium production in b -hadron decays and first evidence for the decay Bs0. _European Physical Journal C_. 2017. Vol. 77, núm. 609, pàgs. 1-18. [consulta: 23 de gener de 2026]. ISSN: 1434-6044. [Disponible a: https://hdl.handle.net/2445/186477]