Abstract
The global fit of the Standard Model to electroweak precision data, routinely performed by the LEP electroweak working group and others, demonstrated impressively the predictive power of electroweak unification and quantum loop corrections. We have revisited this fit in view of (i) the development of the new generic fitting package Gfitter, (ii) the insertion of constraints from direct Higgs searches at LEP and the Tevatron, and (iii) a more thorough statistical interpretation of the results. Gfitter is a modular fitting toolkit, which features predictive theoretical models as independent plugins, and a statistical analysis of the fit results using toy Monte Carlo techniques. The state-of-the-art electroweak Standard Model is fully implemented, as well as generic extensions to it. This paper introduces the Gfitter project, and presents state-of-the-art results for the global electroweak fit in the Standard Model, and for a model with an extended Higgs sector (2HDM). Numerical and graphical results for fits with and without including the constraints from the direct Higgs searches at LEP and Tevatron are given. Perspectives for future colliders are analysed and discussed. Including the direct Higgs searches, we find M_H=(116.4 +18.3 -1.3) GeV, and the 2sigma and 3sigma allowed regions [114,145] GeV and [[113,168] and [180,225]] GeV, respectively. For the strong coupling strength at fourth perturbative order we obtain alpha_S(M_Z)=0.1193 +0.0028 -0.0027(exp) +- 0.0001(theo). Finally, for the mass of the top quark, excluding the direct measurements, we find m_t=(178.2 +9.8 -4.2) GeV. In the 2HDM we exclude a charged-Higgs mass below 240 GeV at 95% confidence level. This limit increases towards larger tan(beta), where e.g., M_H+-<780 GeV is excluded for tan(beta)=70.
Highlights
Replacement of the sixth sentence in the fourth paragraph in Sect
The correction will correspondingly affect the combined exclusion regions drawn in Figs. 5.2 of the publication, which is, hardly visible due to the large range in tan β shown in these plots
Since our paper QCD corrections to Rb0 have been published [16] that will be included in a future update of our analysis
Summary
Replacement of the sixth sentence in the fourth paragraph in Sect. 1 “Introduction” The sentence should be replaced by “The calculations of the partial and total widths of the Z and of the total width of the W boson have been integrated from the ZFITTER package [1, 2] into the Gfitter subpackage GSM and are co-authored by both groups [3].1It includes up to two-loop electroweak corrections [1, 2, 4,5,6,7,8,9,10,11,12,13] and all known QCD corrections [1, 2, 14].” Correction of Rb0 constraints For the theoretical prediction of the electroweak precision observable Rb0 in the 2HDM we used Eqs.
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