Two-loop electroweak fermionic corrections to sin^2 theta_{eff}^{b anti-b}
High Energy Physics - Phenomenology
2010-04-21 v2
Abstract
We present the first calculation of the two-loop electroweak fermionic correction to the flavour-dependent effective weak-mixing angle for bottom quarks, sin^2 theta_{eff}^{b anti-b}. For the evaluation of the missing two-loop vertex diagrams, two methods are employed, one based on a semi-numerical Bernstein-Tkachov algorithm and the second on asymptotic expansions in the large top-quark mass. A third method based on dispersion relations is used for checking the basic loop integrals. We find that for small Higgs-boson mass values, M_H ~ 100 GeV, the correction is sizable, of order O(10^{-4}).
Cite
@article{arxiv.0811.1364,
title = {Two-loop electroweak fermionic corrections to sin^2 theta_{eff}^{b anti-b}},
author = {M. Awramik and M. Czakon and A. Freitas and B. A. Kniehl},
journal= {arXiv preprint arXiv:0811.1364},
year = {2010}
}
Comments
17 pages, 2 figures, references added, accepted for publication in Nucl. Phys. B