Measurement of the polarized forward-backward asymmetry of s-quarks at SLD

Thesis/Dissertation · Sun Mar 01 00:00:00 EST 1998

DOI:https://doi.org/10.2172/666059· OSTI ID:666059

Narita, Shinya ^[1]

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1. Stanford Univ., CA (United States)

This thesis presents a direct measurement of the parity-violating parameter A_s by analyzing the polarized forward-backward asymmetry of s quarks in e⁺e^- →} Z⁰ → s$$\bar{s}$$. The author has used the data taken at the Stanford Linear Accelerator Center (SLAC), from the SLAC Large Detector (SLD), which records the products of e⁺e^- interactions at a center of mass energy √s = 91.2 GeV at the SLAC Linear Collider (SLC). The unique features of the SLC/SLD experimental apparatus provide interesting tests of the electroweak and the QCD physics. The small, stable SLC beam spot, and the precise tracking capability of the SLD allow the isolation of light flavor events. Charged hadrons are identified over wide momentum range with the Cherenkov Ring Imaging Detector (CRID). High momentum charged kaon, Λ⁰/$$\bar{Λ}$$⁰, and K$$0\atop{s}$$ are used to select Z⁰ → s$$\bar{s}$$ events and to identify the s-quark direction. The averaged polarization was 63.0% in 1993 SLD run and 77.3% in 1994-95 run. The author obtained A_s = 0.86 ± 0.17(stat.) ± 0.10(syst.). This value is consistent with the prediction from the Standard Model and with the values of A_b measurements from SLD and LEP experiments.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 666059
• Report Number(s): SLAC-R-520; ON: DE98059291; TRN: US200305%%638
• Resource Relation: Other Information: TH: Thesis (Ph.D.); Supercedes report DE98059291; Thesis submission information not provided; TH: Thesis (Ph.D.); PBD: Mar 1998; PBD: 1 Mar 1998
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
36 MATERIALS SCIENCE
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
A CENTERS
ASYMMETRY
FORECASTING
HADRONS
LINEAR COLLIDERS
PHYSICS
POLARIZATION
QUANTUM CHROMODYNAMICS
S QUARKS
STANDARD MODEL
STANFORD LINEAR ACCELERATOR CENTER