Measurement of the ηc(1 S) production cross-section in p p collisions at √s=13TeV

Research output: Contribution to journalArticlepeer-review

Authors

  • LHCb Collaboration

Colleges, School and Institutes

External organisations

  • Nikhef National Institute for Subatomic Physics
  • Universität Zürich
  • University of Liverpool
  • Universidad de Santiago de Compostela
  • BRISTOL UNIVERSITY
  • Université Clermont Auvergne
  • University of Michigan, Ann Arbor.
  • Istituto Nazionale di Fisica Nucleare, Sezione di Milano
  • University of Cincinnati
  • Laboratori Nazionali dell'Infn di Frascati
  • Technische Universität Dortmund
  • European Organization for Nuclear Research (CERN)
  • University of Glasgow
  • Universitat Autònoma de Barcelona
  • Petersburg Nuclear Physics Institute (PNPI)
  • Imperial College London
  • Universidade Federal Do Rio de Janeiro (UFRJ)
  • IN2P3
  • Sezione INFN di Firenze
  • Sezione INFN di Ferrara
  • Ruprecht-Karls-Universität Heidelberg
  • CNRS/IN2P3
  • Institute for High Energy Physics (IHEP)
  • Yandex School of Data Analysis
  • INFN Sezione di Cagliari
  • THE UNIVERSITY OF WARWICK
  • Institute of Physics

Abstract

Using a data sample corresponding to an integrated luminosity of 2.0 fb-1, collected by the LHCb experiment, the production of the ηc(1 S) state in proton–proton collisions at a centre-of-mass energy of s=13TeV is studied in the rapidity range 2.0 < y< 4.5 and in the transverse momentum range 6.5<pT<14.0GeV. The cross-section for prompt production of ηc(1 S) mesons relative to that of the J/ ψ meson is measured using the pp¯ decay mode and is found to be σηc(1S)/σJ/ψ=1.69±0.15±0.10±0.18. The quoted uncertainties are, in order, statistical, systematic and due to uncertainties on the branching fractions of the J/ψ→pp¯ and ηc→pp¯ decays. The prompt ηc(1 S) production cross-section is determined to be σηc(1S)=1.26±0.11±0.08±0.14μb, where the last uncertainty includes that on the J/ ψ meson cross-section. The ratio of the branching fractions of b-hadron decays to the ηc(1 S) and J/ ψ states is measured to be Bb→ηcX/Bb→J/ψX=0.48±0.03±0.03±0.05, where the last uncertainty is due to those on the branching fractions of the J/ψ→pp¯ and ηc→pp¯ decays. The difference between the J/ ψ and ηc(1 S) masses is also determined to be 113.0±0.7±0.1MeV, which is the most precise single measurement of this quantity to date.

Details

Original languageEnglish
Article number191
JournalEuropean Physical Journal C
Volume80
Issue number3
Publication statusPublished - 2 Mar 2020