Parity Violating Asymmetries and Weak Neutral Currents [Thesis]

Technical Report · Mon Dec 01 04:00:00 EST 1980

DOI:https://doi.org/10.2172/1453971· OSTI ID:1453971

Tsao, Thomas ^[1]

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1. SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., CA (United States)

The vector and axial couplings of leptons and quarks to the weak neutral current are studied by focusing on the parity violating asymmetries which arise in the following scattering processes: polarized-electron nucleon elastic collisions, dilepton production in polarized-proton proton scattering, polarized-electron positron annihilation into fermion pairs, and polarized-electron electron collisions. Numerical results are presented for the weinberg-Salam model of electroweak interactions. It is found that at q² = 1 GeV², the parity violating asymmetries for elastic electron nucleon collisions are typically $$\mathcal{O}(10^{-5})$$ for proton, neutron, and deuteron targets. For dilepton production at presently available energies of s = 10³ GeV², the parity violating asymmetries are $$\mathcal{O}(10^{-2})$$ while at much higher energies s = 6.4 x 10⁵ GeV², the asymmetries are $$\mathcal{O}(10^{-1})$$. Electron positron annihilation into μ⁺μ^-, $$q\overline{q}$$ and e⁺e^- give parity violating asymmetries that are typically $$\mathcal{O}(10^{-1} to 1)$$ for s near the Z^o pole. Polarized-electron electron scattering yields parity violating asymmetries of $$\mathcal{O}(10^{-2})$$ at s ≈ 10⁴ GeV². The restrictions imposed on the parameters of the six-quark model by the neutral kaon system are discussed - with QCD effects included in the leading logarithmic approximation. The dependence of the CP violation parameter ε', the b-quark lifetime, and the ratio of decay widths Γ(b → ux)/Γ (b → cx) on the six-quark model parameters is also discussed.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1453971
• Report Number(s): SLAC--233; SLAC-R--233
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS