English

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

High Energy Physics - Phenomenology 2008-11-26 v1

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.

Keywords

Cite

@article{arxiv.hep-ph/0407317,
  title  = {Complete Two-Loop Electroweak Fermionic Corrections to sin^2(theta_eff) and Indirect Determination of the Higgs Boson Mass},
  author = {M. Awramik and M. Czakon and A. Freitas and G. Weiglein},
  journal= {arXiv preprint arXiv:hep-ph/0407317},
  year   = {2008}
}

Comments

4 pages, 2 figures