Measurement of the partial decay width $R_b^0 = \Gamma_{b\bar{b}}/\Gamma_{had}$ of the $Z$ with the DELPHI detector at LEP

Abstract

Link to publication Citation for published version (APA): Abreu, P., Agasi, E. E., Boudinov, E., Hao, W., Holthuizen, D. J., Kluit, P. M., ... van Eldik, J. E. (1996). Measurement of the partial decay width R_b^0 = Gamma_b\overline{b}/Gamma_had of the Z with the DELPHI detector at LEP. Zeitschrift für Physik. C, Particles and Fields, 70, 531. https://doi.org/10.1007/s002880050131 General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 29 Apr 2019Z. Phys. C 70, 531-547 (1996) ZEITSCHRIFT FÜR PHYSIK C Abstract. The partial decay width of the Z to bb quark pairs has been measured by the DELPHI detector at LEP. Bhadrons, containing b-quarks, were tagged by several methods using tracks with large impact parameters to the primary vertex complemented sometimes by event shape variables or using leptons with high transverse momentum relative to the hadron. In order to reduce the systematic uncertainties, in all methods the b-tagging efficiency has been extracted directly from the data. Combining all methods, the value: Γ bb Γ had = 0.2216 ± 0.0016(stat.) ± 0.0021(syst.)was found, where the cc production fraction was fixed to its Standard Model value.