====== TTP10-05 Adler Function, Bjorken Sum Rule, and the Crewther Relation to Order alpha_s^$ in a General Gauge Theory ======
 
 
   <hidden TTP10-05  Adler Function, Bjorken Sum Rule, and the Crewther Relation to Order alpha_s^$ in a General Gauge Theory > We compute, for the first time, the order alpha_s^4
 contributions to the Bjorken sum rule for  polarized electron-nucleon  scattering
 and to the (non-singlet) Adler function for the  case of a  generic colour gauge group.
 We confirm at the same order a (generalized)
 Crewther relation which provides a strong test
 of the correctness of our previously obtained  results: the  QCD Adler function
 and the five-loop \beta-function in  quenched QED.
 In particular, the appearance of an  irrational contribution proportional
 to zeta_3 in the latter   quantity  is confirmed.
 We obtain  the {\em commensurate} scale equation relating the  effective
 strong coupling constants as inferred from the Bjorken sum rule and from
 the Adler function at order  alpha_s^4.
 </hidden>
|**P.A. Baikov, K.G. Chetyrkin and  J.H. K\"uhn...**  | 
|** Phys.Rev.Lett. 104 132004 2010  **  |
| {{preprints:2010:ttp10-05.pdf|PDF}} {{preprints:2010:ttp10-05.ps|PostScript}} [[http://arxiv.org/abs/1001.3606|arXiv]]   |
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