====== TTP04-30 Perturbative QCD and  tau-decays ======
 
 
<hidden TTP04-30  Perturbative QCD and  tau-decays > The current status of the higher order QCD corrections to the width of
 the tau is discussed. We report on the result of  the 
 first complete  calculation of the quadratic
 quark mass correction to the correlator of the two  currents
 relevant for the strangeness-changing  semihadronic tau-decay rate 
 (including its **real**  part at the four-loop level. 
 We discuss  phenomenological implications   for determination of m_s.
 </hidden>
|**P.A. Baikov, K.G. Chetyrkin and  J.H.K\"uhn**  | 
|**  Nucl. Phys. Proc. Suppl.  144 81-87 2005  **  |
| {{preprints:2004:ttp04-30.pdf|PDF}} {{preprints:2004:ttp04-30.ps|PostScript}}   |
| |