The production of the ηc(1S) state in proton-proton collisions is probed via its decay to the p anti-p final state with the LHCb detector, in the rapidity range 2.0 < y < 4.5 and in the meson transverse-momentum range p_T > 6.5 GeV/c. The cross-section for prompt production of ηc(1S) mesons relative to the prompt J/ψ cross-section is measured, for the first time, to be σ_ηc(1S)/σ_J/ψ = 1.74 ± 0.29 ± 0.28 ± 0.18_B at a centre-of-mass energy √s = 7 TeV using data corresponding to an integrated luminosity of 0.7 fb^−1, and σ_ηc(1S)/σ_J/ψ = 1.60 ± 0.29 ± 0.25 ± 0.17_B at √s = 8 TeV using 2.0 fb^−1. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the ηc(1S) and J/ψ decays to the p anti-p final state. In addition, the inclusive branching fraction of b-hadron decays into ηc(1S) mesons is measured, for the first time, to be B(b → ηc X) = (4.88 ± 0.64 ± 0.29 ± 0.67_B) × 10^−3, where the third uncertainty includes also the uncertainty on the J/ψ inclusive branching fraction from b-hadron decays. The difference between the J/ψ and ηc(1S) meson masses is determined to be 114.7 ± 1.5 ± 0.1 MeV/c^2.

Aaij, R., Abellán Beteta, C., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., et al. (2015). Measurement of the ηc(1S) Production Cross-Section in Proton–Proton Collisions via the Decay ηc(1S) → p anti-p. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 75(7), 1-12 [10.1140/epjc/s10052-015-3502-x].

Measurement of the ηc(1S) Production Cross-Section in Proton–Proton Collisions via the Decay ηc(1S) → p anti-p

CARBONE, ANGELO;GALLI, DOMENICO;MOGGI, NICCOLO';MUSSINI, MANUEL;PATRIGNANI, CLAUDIA;PERAZZINI, STEFANO;VAGNONI, VINCENZO MARIA;ZANGOLI, MARIA;
2015

Abstract

The production of the ηc(1S) state in proton-proton collisions is probed via its decay to the p anti-p final state with the LHCb detector, in the rapidity range 2.0 < y < 4.5 and in the meson transverse-momentum range p_T > 6.5 GeV/c. The cross-section for prompt production of ηc(1S) mesons relative to the prompt J/ψ cross-section is measured, for the first time, to be σ_ηc(1S)/σ_J/ψ = 1.74 ± 0.29 ± 0.28 ± 0.18_B at a centre-of-mass energy √s = 7 TeV using data corresponding to an integrated luminosity of 0.7 fb^−1, and σ_ηc(1S)/σ_J/ψ = 1.60 ± 0.29 ± 0.25 ± 0.17_B at √s = 8 TeV using 2.0 fb^−1. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the ηc(1S) and J/ψ decays to the p anti-p final state. In addition, the inclusive branching fraction of b-hadron decays into ηc(1S) mesons is measured, for the first time, to be B(b → ηc X) = (4.88 ± 0.64 ± 0.29 ± 0.67_B) × 10^−3, where the third uncertainty includes also the uncertainty on the J/ψ inclusive branching fraction from b-hadron decays. The difference between the J/ψ and ηc(1S) meson masses is determined to be 114.7 ± 1.5 ± 0.1 MeV/c^2.
2015
Aaij, R., Abellán Beteta, C., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., et al. (2015). Measurement of the ηc(1S) Production Cross-Section in Proton–Proton Collisions via the Decay ηc(1S) → p anti-p. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 75(7), 1-12 [10.1140/epjc/s10052-015-3502-x].
Aaij, R.; Abellán Beteta, C.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkha...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/515023
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