Measurements of Rb in e+e− collisions at s between 182 and 209 GeV

• Published in: Physics letters. B Vol. 609; no. 3-4; pp. 212 - 225
• Main Authors: Ainsley, C., Alexander, G., Amaral, P., Anagnostou, G., Bailey, I., Bell, K.W., Bellerive, A., Benelli, G., Bethke, S., Bock, P., Brown, R.M., Campana, S., Carter, A.A., Carter, J.R., Chang, C.Y., Csilling, A., Cuffiani, M., Desch, K., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Etzion, E., Fabbri, F., Fanfani, A., Fleck, I., Ford, M., Gagnon, P., Giacomelli, P., Giunta, M., Goldberg, J., Gross, E., Günther, P.O., Gupta, A., Hanson, G.G., Hauschild, M., Hemingway, R.J., Jeremie, H., Jovanovic, P., Kanzaki, J., Karlen, D., Kawagoe, K., Kawamoto, T., Kellogg, R.G., Kennedy, B.W., Kobayashi, T., Kobel, M., Krämer, T., Krieger, P., von Krogh, J., Kuhl, T., Letts, J., Lloyd, S.L., Ludwig, A., Martin, A.J., Masetti, G., Mashimo, T., Mättig, P., Menges, W., Merritt, F.S., Mes, H., Meyer, N., Michelini, A., Mikenberg, G., Mohr, W., Montanari, A., Mori, T., Nakamura, I., Nanjo, H., Neal, H.A., Nisius, R., Oh, A., Pahl, C., Pilcher, J.E., Rembser, C., Rozen, Y., Saeki, T., Sarkisyan, E.K.G., Schaile, O., Schieck, J., Schörner-Sadenius, T., Schröder, M., Seuster, R., Shears, T.G., Sobie, R., Spano, F., Stahl, A., Torrence, E., Toya, D., Trigger, I., Ueda, I., Vollmer, C.F., Voss, H., Vossebeld, J., Ward, C.P., Ward, D.R., Wells, P.S., Wyatt, T.R., Zer-Zion, D., Zivkovic, L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10.03.2005; Elsevier Science
• Subjects: Exact sciences and technology; Physics; The physics of elementary particles and fields; Lifetime; Leptons; Center of mass; Standard model; Quarks; Positron annihilation; Cross sections
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2005.01.031

Measurements of Rb, the ratio of the bb¯ cross-section to the qq¯ cross-section in e+e− collisions, are presented. The data were collected by the OPAL experiment at LEP at centre-of-mass energies between 182 and 209 GeV. Lepton, lifetime and event-shape information is used to tag events containing b quarks with high efficiency. The data are compatible with the Standard Model expectation. The mean ratio of the eight measurements reported here to the Standard Model prediction is 1.055±0.031±0.037, where the first error is statistical and the second systematic.