Precision luminosity measurements at LHCb

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  • LHCb Collaboration
  • R. Aaij
  • B. Adeva
  • M. Adinolfi
  • A. Affolder
  • Z. Ajaltouni
  • S. Akar
  • J. Albrecht
  • F. Alessio
  • M. Alexander
  • S. Ali
  • G. Alkhazov
  • P. Alvarez Cartelle
  • Jr A. Alves
  • S. Amato
  • S. Amerio
  • Y. Amhis
  • L. An
  • L. Anderlini
  • J. Anderson
  • R. Andreassen
  • M. Andreotti
  • J. E. Andrews
  • R. B. Appleby
  • O. Aquines Gutierrez
  • F. Archilli
  • A. Artamonov
  • M. Artuso
  • E. Aslanides
  • G. Auriemma
  • M. Baalouch
  • S. Bachmann
  • J. J. Back
  • A. Badalov
  • C. Baesso
  • W. Baldini
  • R. J. Barlow
  • C. Barschel
  • S. Barsuk
  • W. Barter
  • Simone Bifani
  • N. Farley
  • P. Griffith
  • Ian Kenyon
  • Cristina Lazzeroni
  • A. Mazurov
  • J. McCarthy
  • Chris Parkinson
  • L. Pescatore
  • Nigel Watson
  • Matt Williams

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  • Nikhef National Institute for Subatomic Physics
  • Universidad de Santiago de Compostela
  • University of Bristol
  • University of Liverpool
  • LPC
  • Aix Marseille University
  • TU Dortmund University, Germany
  • CERN
  • University of Glasgow
  • Petersburg Nuclear Physics Institute (PNPI)
  • Universidade Federal Do Rio de Janeiro
  • Department of Physics and Astronomy and INFN
  • IN2P3
  • Tsinghua University
  • University of Florence
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  • University of Cincinnati
  • University of Ferrara
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  • Max-Planck-Institut für Kernphysik (MPIK)
  • Institute for High Energy Physics (IHEP)
  • Syracuse University
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  • Ruprecht-Karls-Universität Heidelberg
  • University of Warwick
  • Universitat Autonoma de Barcelona
  • Pontifícia Universidade Católica Do Rio de Janeiro
  • University of Cambridge


Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy √s. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for √s = 2.76, 7 and 8 TeV (proton-proton collisions) and for √sNN = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves significantly the consistency of the results. For proton-proton interactions at √s = 8 TeV a relative precision of the luminosity calibration of 1.47% is obtained using van der Meer scans and 1.43% using beam-gas imaging, resulting in a combined precision of 1.12%. Applying the calibration to the full data set determines the luminosity with a precision of 1.16%. This represents the most precise luminosity measurement achieved so far at a bunched-beam hadron collider.


Original languageEnglish
Article numberP12005
Number of pages91
JournalJournal of Instrumentation
Issue number12
Publication statusPublished - 5 Dec 2014


  • Instrumentation for particle accelerators and storage rings - high energy (linear accelerators synchrotrons), Pattern recognition cluster finding calibration and fitting methods

ASJC Scopus subject areas