Measurement of the forward-backward asymmetry of e(+)e(-)-]z-]b(b)over-bar using prompt leptons and a lifetime tag

Abstract
The forward-backward asymmetry of the processe + e −→Z→b bb¯ has been measured using events collected by the DELPHI experiment during the 1991 and 1992 LEP runs. This data sample corresponded to 884 000 hadronicZ decays at a centre-of-mass energy s√∼MZ . The tagging of b-quark events was performed using two approaches; the first was based on the semileptonic decay channelsb→X+μ andb→X+e, the second used a lifetime tag with jet-charge reconstruction. The results of these two methods were combined to give Abb¯FB=0.107±0.011(stat.+syst.+mixing). With the semileptonic sample, the forward-backward asymmetry of the processe + e −→Z→ cc¯ was also measured to be Acc¯FB=0.083±0.022(stat.)±0.016(syst.). The effective value of the Weinberg mixing angle derived from these measurements was sin2θlepeff=0.2294±0.0021.
Description
Bibliographic reference
DELPHI Collaboration (Abreu, P. Ferrer Soria, Antonio Cases Ruiz, Manuel Ramón Castillo Giménez, María Victoria Higón Rodríguez, Emilio 1995 Measurement of the forward-backward asymmetry of e(+)e(-)-]z-]b(b)over-bar using prompt leptons and a lifetime tag Zeitschrift für Physik C-Particles and Fields 65 4 569 585
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