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Absolute luminosity measurements with the LHCb detector at the LHC

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LHCb Collaboration (Including: Back, J. J., Dossett, D., Gershon, T. J., Harrison, P. F., Kreps, Michal, Latham, Thomas, Pilar, T., Poluektov, Anton, Reid, Matthew M., Whitehead, M. (Mark) and Williams, M. P.). (2012) Absolute luminosity measurements with the LHCb detector at the LHC. Journal of Instrumentation, Volume 7 (Number 1). Article number P01010. ISSN 1748-0221

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Abstract

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ''van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overal precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.

Item Type: Journal Article
Subjects: Q Science > QC Physics
Divisions: Faculty of Science > Physics
Library of Congress Subject Headings (LCSH): Colliders (Nuclear physics), Proton-proton interactions, Large Hadron Collider (France and Switzerland)
Journal or Publication Title: Journal of Instrumentation
Publisher: IOP Publishing Ltd
ISSN: 1748-0221
Official Date: 10 January 2012
Dates:
DateEvent
10 January 2012Published
Volume: Volume 7
Number: Number 1
Article Number: Article number P01010
Identification Number: 10.1088/1748-0221/7/01/P01010
Status: Peer Reviewed
Publication Status: Published
Access rights to Published version: Open Access
Funder: Brazil. Coordenação do Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Financiadora de Estudos e Projetos (Brazil) (FINEP), European Organization for Nuclear Research (CERN), Guo jia zi ran ke xue ji jin wei yuan hui (China) [National Natural Science Foundation of China] (NSFC), Centre national de la recherche scientifique (France) (CNRS), Institut national de physique nucléaire et de physique des particules (IN2P3), Germany. Bundesministerium für Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Hermann von Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF), Max-Planck-Gesellschaft zur Förderung der Wissenschaften [Max Planck Society for the Advancement of Science], Istituto nazionale di fisica nucleare (INFN), Science Foundation Ireland (SFI), Stichting voor Fundamenteel Onderzoek der Materie (FOM) [Foundation for Fundamental Research on Matter], Nederlandse Organisatie voor Wetenschappelijk Onderzoek [Netherlands Organisation for Scientific Research] (NWO), SCSR (Poland), Autoritatea Nationala pentru Cercetare Stiintifica (ANCS), Russia (Federation). Ministerstvo obrazovanii︠a︡ i nauki [Ministry of Education and Science], Federalʹnoe agentstvo po atomnoĭ ėnergii (Russia), Spain. Ministerio de Ciencia e Innovación (MICINN), Galicia (Spain : Region). Xunta, Catalonia (Spain), Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung [Swiss National Science Foundation] (SNSF), Switzerland. Staatssekretariat für Ausbildung und Forschung (SER), Nat︠s︡ionalʹna akademii︠a︡ nauk Ukraïny (NAS), Science and Technology Facilities Council (Great Britain) (STFC), National Science Foundation (U.S.) (NSF), Seventh Framework Programme (European Commission) (FP7), Auvergne (France)
References:

[1] M. Mangano, Motivations and precision targets for an accurate luminosity determination, in
proceedings of LHC Lumi Days: LHC Workshop on LHC Luminosity Calibration, CERN (2011),
CERN-Proceedings-2011-001.
[2] J. Anderson, Prospects for indirect luminosity measurements at LHCb, in proceedings of LHC Lumi
Days: LHC Workshop on LHC Luminosity Calibration, CERN (2011), CERN-Proceedings-2011-001.
[3] R. Thorne, A. Martin, W. Stirling and G. Watt, Parton distributions and QCD at LHCb, in
proceedings of XVI International Workshop on Deep-Inelastic Scattering and Related Topics,
London, England, April 2008, arXiv:0808.1847.
[4] F. De Lorenzi, PDF sensitivity studies using electroweak processes at LHCb, in proceedings of XVIII
International Workshop on Deep-Inelastic Scattering and Related Subjects, Convitto della Calza,
Firenze, Italy (2010) arXiv:1011.4260.
[5] C. Møller, General properties of the characteristic matrix in the theory of elementary particles,
K. Danske Vidensk. Selsk. Mat.-Fys. Medd. 1 (1945);
for later papers see e.g. O. Napoly, The luminosity for beam distributions with error and wake field
effects in linear colliders, Particle Acc. 40 (1993) 181;
W. Herr, B. Muratori, Concept of luminosity, in proceedings of CERN Accelerator School (2003) 361.
[6] The TOTEM collaboration, TOTEM Technical Design Report, CERN-LHCC-2004-002,
TOTEM-TDR-001.
[7] The ATLAS collaboration, ATLAS Forward Detectors for Measurement of Elastic Scattering and
Luminosity, CERN-LHCC-2008-004, ATLAS TDR 18 (2008).
[8] S. van der Meer, Calibration of the effective beam height in the ISR, CERN report (1968)
ISR-PO/68-31.
[9] H. Burkhardt and P. Grafstrom, ¨ Absolute luminosity from machine parameters,
CERN-LHC-PROJECT-Report-1019 (2007).
[10] M. Ferro-Luzzi, Proposal for an absolute luminosity determination in colliding beam experiments
using vertex detection of beam-gas interactions, Nucl. Instrum. Meth. A 553 (2005) 388,
[CERN-PH-EP-2005-023].
[11] R. Aaij et al, The LHCb Collaboration, Prompt K0
s production in pp collisions at p
s = 0:9 TeV, Phys.
Lett. B 693 (2010) 69, [CERN-PH-EP-2010-027] [arXiv:1008.3105].
[12] V. Balagura, Luminosity measurements in the first LHCb data, in proceedings of 2010 Rencontres de
Moriond (QCD), La Thuile (AO), Italy (2010).
[13] P. Hopchev, The beam-gas method for luminosity measurement at LHCb, in proceedings of 2010
Rencontres de Moriond Electroweak Interactions and Unified Theories, La Thuile (AO), Italy (2010),
arXiv:1005.4398.
[14] K. Oyama, Analysis of the May 2010 van der Meer scan in ALICE, in proceedings of LHC Lumi
Days: LHC Workshop on LHC Luminosity Calibration, CERN (2011), CERN-Proceedings-2011-001;
ATLAS collaboration, Luminosity Determination in pp Collisions at p
s = 7 TeV Using the ATLAS
Detector at the LHC, Eur. Phys. J. C71 (2011) 1630, [CERN-PH-EP-2010-069]
[arXiv:1101.2185];
CMS collaboration, Measurement of CMS Luminosity, CMS-PAS-EWK-10-004.
[15] V. Balagura, Notes on van der Meer Scan for Absolute Luminosity Measurement, Nucl. Instrum.
Meth. A 654 (2011) 643, [arXiv:1103.1129].
[16] J. Bosser et al., Transverse Emittance Measurement With a Rapid Wire Scanner at the CERN SPS,
Nucl. Instrum. Meth. A 235 (1985) 475.
[17] The LHCb collaboration, The LHCb Detector at the LHC, 2008 JINST 3 S08005.
[18] N.Yu. Zaitsev, Study of the LHCb pile-up trigger and the Bs ! Jyf decay, NIKHEF, Amsterdam
(2000) CERN-THESIS-2000-043.
[19] J.J. Gras, M. Ludwig and P. Odier, The 2010 LHC DC BCT measurement system and its main sources
of uncertainties, CERN-LHC-Project-Note-432;
D. Belohrad, J.J. Gras and M. Ludwig, The 2010 LHC ring Fast BCT measurement system and its
main sources of uncertainties, CERN-LHC-Project-Note-433;
D. Belohrad et al., Commissioning and first performance of the LHC beam current measurement
systems, 1
st IPAC, Kyoto, Japan, 23–28 May 2010.
[20] G. Anders et al., LHC bunch current normalisation for the April-May 2010 luminosity calibration
measurements, CERN-ATS-Note-2011-004 (2011).
[21] C. Ohm and T. Pauly, The ATLAS beam pick-up based timing system, Nucl. Instrum. Meth. A 623
(2010) 558.
[22] A. Alici et al., LHC Bunch Current Normalisation for the October 2010 Luminosity Calibration
Measurements, CERN-ATS-Note-2011-016 PERF.
[23] C. Lasseur et al., Geometrie du LHC: points caracteristiques, formules de transformation,
CERN-LHC-Project-Note-95 (1997).
[24] S. White, Determination of the Absolute Luminosity at the LHC, Universite Paris-Sud 11 (2010) ´
CERN-THESIS-2010-139, LAL-10-154.
[25] R. Aaij et al, The LHCb collaboration, Measurement of the inclusive f cross-section in pp collisions
at ps = 7 TeV, Phys. Lett. B 703 (2011) 267, [CERN-PH-EP-2011-106]
[arXiv:1107.3proceedin935].
URI: http://wrap.warwick.ac.uk/id/eprint/47921

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