TY  - JOUR
AU  - LHCb Collaboration (Aaij, R. et al
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
AU  - Ruiz Valls, P.
AU  - Sanchez Mayordomo, C.
PY  - 2014
DA  - 2014//
TI  - Precision luminosity measurements at LHCb
T2  - J. Instrum.
JO  - Journal of Instrumentation
SP  - P12005 - 91pp
VL  - 9
PB  - Iop Publishing Ltd
KW  - Pattern recognition
KW  - cluster finding
KW  - calibration and fitting methods
KW  - Instrumentation for particle accelerators and storage rings – high energy (linear accelerators
KW  - synchrotrons)
AB  - Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy root s. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for root s = 2.76, 7 and 8TeV (proton-proton collisions) and for root s(NN) = 5TeV (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 root s = 8TeV 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.
SN  - 1748-0221
UR  - http://arxiv.org/abs/1410.0149
UR  - https://doi.org/10.1088/1748-0221/9/12/P12005
DO  - 10.1088/1748-0221/9/12/P12005
LA  - English
N1  - WOS:000345859200021
ID  - LHCbCollaborationAaij_etal2014
ER  -