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Results for Precision Observables in the Electroweak Standard Model at Two-Loop Order and Beyond

G. Weiglein
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Abstract

Higher-order contributions to the precision observables Δr, \sin^2θ_eff and Γ_l are discussed. The Higgs-mass dependence of the observables is investigated at the two-loop level, and exact results are derived for the Higgs-dependent two-loop corrections associated with fermions. The top-quark corrections are compared with the results obtained by an expansion in the top-quark mass up to next-to-leading order. For the pure fermion-loop contributions to Δr results up to four-loop order are derived. They allow to investigate the validity of the commonly used resummation of the leading fermionic contributions to Δr.

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G. Weiglein. 1998-07-02. Results for Precision Observables in the Electroweak Standard Model at Two-Loop Order and Beyond. https://arxiv.org/abs/hep-ph/9807222

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