Direct Measurement of A{sub b} at the Z{sup 0} Pole Using a Lepton Tag
- SLAC
The authors present a direct measurement of the parity violation parameter A{sub b}, derived from the left-right forward-backward asymmetry of b quarks tagged via leptons from semileptonic decays. The lepton identification algorithm combines information from tracking, calorimetry and from the SLD Cherenkov Ring Imaging Detector. The value of Ab is extracted using a maximum likelihood fit to the differential cross section for fermion production. Vertexing information and decay kinematics have been used to discriminate among the different sources of tagged leptons. A new treatment of mixing effects and of background contamination has been introduced and a new vertexing algorithm has been used in the muon analysis. Based on the 1993--1998 SLD sample of 550K hadronic Z{sup 0} decays with highly polarized electron beams, they have measured Ab with a {approximately}3% statistical error.
- Research Organization:
- Stanford Linear Accelerator Center, Menlo Park, CA (US)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 764971
- Report Number(s):
- SLAC-PUB-8516
- Country of Publication:
- United States
- Language:
- English
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