A precise measurement of the partial decay width ratio {R {b}}0 = Γ {b {b}}}/Γ { {had}
Abstract
The partial decay width of the Z to b b quark pairs has been measured by the DELPHI detector at LEP using data taken in the years 1992 to 1995. Decays of b-hadrons were tagged by several methods using tracks with large impact parameters and/or reconstructed secondary vertices, complemented by event shape variables. Combining these methods in a multivariate analysis the value \[ \frac{\Gamma(Z \rightarrowb \bar b) } { \Gamma({Z \rightarrow had}) } = 0.21634 \pm 0.00067({stat}) \pm 0.00060 ({syst}) \] was obtained, where the c production fraction was fixed to its Standard Model value.
- Publication:
-
European Physical Journal C
- Pub Date:
- October 1999
- Bibcode:
- 1999EPJC...10..415D