Measurement of charged hadron spectra at the Z⁰ with Cherenkov ring imaging

Thesis/Dissertation · Fri Aug 01 00:00:00 EDT 1997

DOI:https://doi.org/10.2172/663281· OSTI ID:663281

Pavel, Tomas Josef ^[1]

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1. Stanford Univ., CA (United States)

This dissertation attempts to probe hadronization, the process by which the fundamental quarks described by quantum chromodynamics produce the jets of hadrons that the author observed in experiments. The measurements are made using e⁺e^- collisions at the SLAC Linear Collider (SLC), operating at the Z⁰ resonance with the SLC Large Detector (SLD), and the unique capabilities of the SLC/SLD facility are exploited. First, the spectra of charged hadrons (π^±, K^±, and p/$$\bar{p}$$) are measured. This is accomplished with the SLD Cherenkov Ring Imaging Detector (CRID), one of a first generation of devices that have been developed for efficient particle identification over a wide momentum range. The use of the CRID is central to this dissertation, and its design and performance are described in detail here. The measured spectra agree with other measurements at the Z⁰ and extend the momentum coverage. Next, the excellent spatial resolution of the SLD tracking systems, along with the small and stable beam spots of the SLC, is employed to identify jets produced from heavy b or c quarks and to separate them from the remaining light-quark (uds) jets. This removes the effects of heavy quark fragmentation and decays of heavy-quark hadrons from the study of hadronization. The first measurements of particle spectra in light-quark jets are then presented. Finally, the highly-polarized incident electron beam of the SLC, together with the electroweak asymmetries of the quarks, is exploited to separate quark and antiquark jets. Significant differences in quark-antiquark production of protons and of kaons are observed at high momenta. This signal suggests a leading particle effect, where the particles containing the primary quark of a jet are more likely to populate the high-momentum phase space than are other hadrons.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 663281
• Report Number(s): SLAC-R-491; ON: DE98059282; TRN: US200305%%621
• Resource Relation: Other Information: TH: Thesis (Ph.D.); Supercedes report DE98059282; Thesis submission information not provided; TH: Thesis (Ph.D.); PBD: Aug 1997; PBD: 1 Aug 1997
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
C QUARKS
ELECTRON BEAMS
HADRONS
LEADING PARTICLES
LINEAR COLLIDERS
PARTICLE IDENTIFICATION
PHASE SPACE
QUANTUM CHROMODYNAMICS
SPATIAL RESOLUTION
SPECTRA
STANFORD LINEAR ACCELERATOR CENTER