2008/04/30 by G. Cynolter, E. Lendvai · 1 citation
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1140/epjc/s10052-008-0771-7
published as Eur.Phys.J.C58:463-469,2008 · 11 pages, 3 figures, references added,sign correction, conclusion about heavy Higgs has changed
arxiv created 2008/06/23 · arxiv updated 2009/12/01
We calculate the oblique electroweak corrections and confront with the experiments in an extension of the Standard Model. The new fields added are a vector-like weak doublet and a singlet fermion. After electroweak symmetry breaking there is a mixing between the components of the new fields, but no mixing allowed with the standard fermions. Four electroweak parameters, S, T, W, Y are presented in the formalism of Barbieri et al., these are the generalization of the Peskin-Takeuchi S, T, U's. The vector-like extension is slightly constrained, T requires the new neutral fermion masses not to be very far from each other, allowing higher mass difference for higher masses and smaller mixing. S, W, Y gives practically no constraints on the masses. This extension can give a positive contribution to T , allowing a heavy Higgs boson in electroweak precision tests of the Standard Model.