====== TTP06-17 Four-Loop QCD Corrections to the Rho Parameter ======
 
 
   <hidden TTP06-17  Four-Loop QCD Corrections to the Rho Parameter > The four-loop QCD corrections to the electroweak $\rho$-parameter
 arising from top and bottom quark loops are computed. Specifically we
 evaluate the missing ``non-singlet'' piece. Using algebraic methods
 the amplitude is reduced to a set of around 50 new master integrals
 which are calculated with various analytical and numerical
 methods. Inclusion of the newly completed term halves the final value
 of the four-loop correction for the minimally renormalized top-quark
 mass. The predictions for the shift of the weak mixing angle and the
 W-boson mass is thus stabilized.
 </hidden>
|**K.G.~Chetyrkin, M.~Faisst, J.H.~Kuehn, P. Maierhoefer, C. Sturm**  | 
|**  Phys. Rev. Lett.  97 102003 2006  **  |
| {{preprints:2006:ttp06-17.pdf|PDF}} {{preprints:2006:ttp06-17.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/0605201|arXiv]]   |
| |