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Complete Two-Loop Electroweak Fermionic Corrections to sin^2(theta_eff) and Indirect Determination of the Higgs Boson Mass

M. Awramik·M. Czakon·A. Freitas·G. Weiglein
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Abstract

We present a complete calculation of the contributions to the effective leptonic weak mixing angle, sin^2theta_eff, generated by closed fermion loops at the two-loop level of the electroweak interactions. This quantity is the source of the most stringent bound on the mass, M_H, of the only undiscovered particle of the Standard Model, the Higgs boson. The size of the corrections with respect to known partial results varies between -4*10^-5 and -8*10^-5 for a realistic range of M_H from 100 to 300 GeV. This translates into a shift of the predicted (from sin^2theta_eff alone) central value of M_H by +19 GeV, to be compared with the shift induced by a recent change in the measured top quark mass which amounts to +36 GeV. Our result, together with all other known corrections is given in the form of a precise fitting formula to be used in the global fit to the electroweak data.

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M. Awramik, M. Czakon, A. Freitas, G. Weiglein. 2004-07-28. Complete Two-Loop Electroweak Fermionic Corrections to sin^2(theta_eff) and Indirect Determination of the Higgs Boson Mass. https://doi.org/10.1103/physrevlett.93.201805

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