Radiative corrections to e+e- to mu+mu- in the Glashow-Salam-Weinberg model

Thesis



A complete renormalization scheme for the Glashow-Salam-Weinberg model is presented. As input parameters the scheme uses the fine structure constant, α, the muon decay constant, G_μ and the Z° mass, M_Z which are known or will be measured to high accuracy in the near future. These are used along with the Higgs and fermion masses to obtain the W mass, M_W. The full one-loop weak radiative corrections to the longitudinal polarization asymmetry, A_pol, and the forward-backward asymmetry, A_fb, in e⁺e^- → μ⁺μ^- are then calculated both on and off resonance. On resonance the results depend extremely sensitively on the Z mass, M_Z, and to a lesser extent on the top quark mass, m_t, and the Higgs mass, M_H, showing that this is a good place to test the standard model at the one loop level. The results are displayed over the full range of the parameters allowed by experimental and theoretical constraints. It is suggested that sufficiently accurate experiments may be able to set an upper bound on one of m_t or M_H if the other is known. It is noted that on resonance A_pol is only weakly dependent on the beam pipe and on the nature of the outgoing fermions. Comparison is made with other calculations of A_fb and the agreement is found to be good. The predictions are also compared with measurements of A_fb off resonance and are found in all cases to lie within the experimental errors. Previous analyses that indicated a possible discrepancy are shown to be incorrect.

Authors: Stuart, R

• Publication date: 1985
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Subjects: Polarization (Nuclear physics); Radiative corrections; Electroweak interactions