Four-Loop Singlet Contribution to the Parameter
arXiv:hep-ph/0504055 · doi:10.1016/j.physletb.2005.06.085
Abstract
We compute the four-loop contribution to the electroweak parameter induced by the singlet diagrams of the -boson self-energy. The numerical impact on the weak mixing angle and the -boson mass is small.
9 pages, minor changes to match published version, references added