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 √s_NN = 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.

R. Aaij, B. Adeva, M. Adinolfi, A. Affolder, Z. Ajaltouni, S. Akar, et al. (2014). Precision Luminosity Measurements at LHCb. JOURNAL OF INSTRUMENTATION, 9(12), 1-89 [10.1088/1748-0221/9/12/P12005].

Precision Luminosity Measurements at LHCb

CARBONE, ANGELO;GALLI, DOMENICO;MOGGI, NICCOLO';MUSSINI, MANUEL;PATRIGNANI, CLAUDIA;PERAZZINI, STEFANO;VAGNONI, VINCENZO MARIA;ZANGOLI, MARIA;
2014

Abstract

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 √s_NN = 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.
2014
R. Aaij, B. Adeva, M. Adinolfi, A. Affolder, Z. Ajaltouni, S. Akar, et al. (2014). Precision Luminosity Measurements at LHCb. JOURNAL OF INSTRUMENTATION, 9(12), 1-89 [10.1088/1748-0221/9/12/P12005].
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; A...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/393145
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