A precise measurement of ΓZ→bb/ΓZ→hadrons

D Buskulic; I De Bonis; D Decamp; P Ghez; C Goy; JP Lees; MN Minard; B Pietrzyk; F Ariztizabal; P Comas; JM Crespo; M Delfino; I Efthymiopoulos; E Fernandez; M Fernandez-Bosman; V Gaitan; L Garrido; T Mattison; A Pacheco; C Padilla; A Pascual; D Creanza; M de Palma; A Farilla; G Iaselli; G Maggi; S Natali; S Nuzzo; M Quattromini; A Ranieri; G Raso; F Romano; F Ruggieri; G Selvaggi; L Silvestris; P Tempesta; G Zito; Y Chai; H Hu; D Huang; X Huang; J Lin; T Wang; Y Xie; D Xu; R Xu; J Zhang; L Zhang; W Zhao; E Blucher; G Bonvicini; J Boudreau; D Casper; H Drevermann; RW Forty; G Ganis; C Gay; R Hagelberg; J Harvey; J Hilgart; R Jacobsen; B Jost; J Knobloch; I Lehraus; T Lohse; M Maggi; C Markou; M Martinez; P Mato; H Meinhard; A Minten; A Miotto; R Miquel; HG Moser; P Palazzi; JR Pater; JA Perlas; JF Pusztaszeri; F Ranjard; G Redlinger; L Rolandi; J Rothberg; T Ruan; M Saich; D Schlatter; M Schmelling; F Sefkow; W Tejessy; IR Tomalin; R Veenhof; H Wachsmuth; S Wasserbaech; W Wiedenmann; T Wildish; W Witzeling; J Wotschack; Z Ajaltouni; F Badaud; M Bardadin-Otwinowska; R El Fellous

Journal article

A precise measurement of ΓZ→bb/ΓZ→hadrons

D Buskulic, I De Bonis, D Decamp, P Ghez, C Goy, JP Lees, MN Minard, B Pietrzyk, F Ariztizabal, P Comas, JM Crespo, M Delfino, I Efthymiopoulos, E Fernandez, M Fernandez-Bosman, V Gaitan, L Garrido, T Mattison, A Pacheco, C Padilla Show all

Physics Letters B | ELSEVIER SCIENCE BV | Published : 1993

DOI: 10.1016/0370-2693(93)90028-G

Abstract

A measurement of the partial width ratio Γbb Γhad using a method which tags the Z → bb decays through the lif etime of the produced heavy hadrons is presented. This method relies on the tracking precision afforded by a double-sided silicon vertex detector. The tag algorithm makes a probabilistic interpretation of three-dimensional track impact parameters, using the data to measure the resolution. By tagging the two b hadrons separately, both Γbb Γhad and the tag efficiency can be determined from the data. For a 26% efficiency of tagging a single b hadron within the vertex detector solid angle coverage, a purity of 96% is achieved. A value of Γbb Γhad = 0.2192±0.0026(stat.)±0.0016(Γcc/ Γhad) ..

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