====== TTP99-25 Second Order QCD Corrections to $\Gamma(t \to Wb)$ ======
 
 
   <hidden TTP99-25  Second Order QCD Corrections to $\Gamma(t \to Wb)$ > Corrections of $O(\alpha_s^2)$ to the decay of the top quark into a
 W boson and a bottom quark are calculated. The method is based on an
 expansion of the top quark propagator for small external momentum, q, as
 compared to the top quark mass, M_t. The physical point q^2 = M_t^2 is
 reached through Pad\'e approximations.  The described method allows to
 take effects induced by a finite W boson mass into account.  The
 numerical relevance of the result is discussed.  Important cross-checks
 against recent results for the decay rate $b \to u l \bar\nu$ and the
 two-loop QED corrections to $\mu$-decay are performed.
 </hidden>
|**K.G. Chetyrkin, R. Harlander, T. Seidensticker, and M. Steinhauser**  | 
|**  Phys. Rev.  D 60 114015 1999  **  |
| {{preprints:1999:ttp99-25.pdf|PDF}} {{preprints:1999:ttp99-25.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/9906273|arXiv]]   |
| |