Two-loop electroweak fermionic corrections to sinθeffbb¯
Abstract
We present the first calculation of the two-loop electroweak fermionic correction to the flavour-dependent effective weak-mixing angle for bottom quarks, sinθeffbb¯. 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∝100 GeV, the correction is sizable, of order O(10).
- Publication:
-
Nuclear Physics B
- Pub Date:
- May 2009
- DOI:
- 10.1016/j.nuclphysb.2008.12.031
- arXiv:
- arXiv:0811.1364
- Bibcode:
- 2009NuPhB.813..174A
- Keywords:
-
- 12.15.Lk;
- 13.38.Dg;
- 13.66.Jn;
- 14.70.Hp;
- Electroweak radiative corrections;
- Decays of Z bosons;
- Precision mesurements in e<sup>-</sup>e<sup>+</sup> interactions;
- Z bosons;
- High Energy Physics - Phenomenology
- E-Print:
- 17 pages, 2 figures, references added, accepted for publication in Nucl. Phys. B