====== TTP98-22 Two-loop QCD corrections to top quark width ======
 
 
   <hidden TTP98-22  Two-loop QCD corrections to top quark width > We present O(alpha_s^2) corrections to the decay t-->bW in the limit
 of a very large top quark mass, m_t >> m_W.  We find that the
 O(alpha_s^2) effects decrease the top quark decay width Gamma_t by
 about 2%: Gamma_t = Gamma_0(1-0.8alpha_s(m_t)-1.7alpha_s^2).  The
 complete corrections are smaller by about 24% than their estimate
 based on the BLM effects O(beta_0 alpha_s^2).  We explain how to
 compute a new type of diagrams which contribute to Gamma(t --> bW) at
 the O(alpha_s^2) level.
 </hidden>
|**Andrzej Czarnecki and Kirill Melnikov**  | 
|** Nucl. Phys. B 544 520 1999  **  |
| {{preprints:1998:ttp98-22.pdf|PDF}} {{preprints:1998:ttp98-22.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/9806244|arXiv]]   |
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