Precision luminosity measurements at LHCb

Aaij, R. et al. (2014) Precision luminosity measurements at LHCb. Journal of Instrumentation, 9, P12005. (doi: 10.1088/1748-0221/9/12/P12005)

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 √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.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Pappagallo, Dr Marco and Dean, Cameron and Alexander, Dr Michael and Beddow, John and Spradlin, Dr Patrick and Ogilvy, Mr Stephen and Soler, Professor Paul and Borghi, Dr Silvia and Karodia, Sarah and Eklund, Prof Lars and Longstaff, Iain Richard and Hynds, Dr Daniel
• Authors: Aaij, R., Affolder, A., Akiba, K., Alexander, M., Ali, S., Appleby, R. B., Artuso, M., Beddow, J., Bay, A., Behrendt, O., Benton, J., Beuzekom, M. v., Bjørnstad, P. M., Bogdanova, G., Borghi, S., Borgia, A., Bowcock, T. J. V., Brand, J. v. d., Brown, H., Buytaert, J., Callot, O., Carroll, J., Casse, G., Collins, P., Capua, S. D., Doets, M., Donleavy, S., Dossett, D., Dumps, R., Eckstein, D., Eklund, L., Farinelli, C., Farry, S., Ferro-Luzzi, M., Frei, R., Garofoli, J., Gersabeck, M., Gershon, T., Gong, A., Gong, H., Gordon, H., Haefeli, G., Harrison, J., Heijne, V., Hennessy, K., Hulsbergen, W., Huse, T., Hutchcroft, D., Jaeger, A., Jalocha, P., Jans, E., John, M., Keaveney, J., Ketel, T., Korolev, M., Kraan, M., Laštovička, T., Lafferty, G., Latham, T., Lefeuvre, G., Leflat, A., Liles, M., Lysebetten, A. v., MacGregor, G., Marinho, F., McNulty, R., Merkin, M., Moran, D., Mountain, R., Mous, I., Mylroie-Smith, J., Needham, M., Nikitin, N., Noor, A., Oblakowska-Mucha, A., Papadelis, A., Pappagallo, M., Parkes, C., Patel, G. D., Rakotomiaramanana, B., Redford, S., Reid, M., Rinnert, K., Rodrigues, E., Saavedra, A. F., Schiller, M., Schneider, O., Shears, T., Coutinho, R. S., Smith, N. A., Szumlak, T., Thomas, C., Tilburg, J. v., Tobin, M., Velthuis, J., Verlaat, B., Viret, S., Volkov, V., Wallace, C., Wang, J., Webber, A., Whitehead, M., Zverev, E., Dean, C.-T., Hynds, D., Karodia, S., Longstaff, I., Ogilvy, S., Soler, F.J.P., and Spradlin, P.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Journal of Instrumentation
• Publisher: Institute of Physics Publishing Ltd.
• ISSN: 1748-0221
• ISSN (Online): 1748-0221
• Copyright Holders: Copyright © 2014 CERN for the benefit of the LHCb collaboration.
• First Published: First published in Journal of Instrumentation 9:P12005
• Publisher Policy: Reproduced under a Creative Commons License