Quark Mass and Field Anomalous Dimensions to ${\cal O}(\alpha_s^5)$
  We present the results of the first complete analytic calculation of the quark mass and field anomalous dimensions to ${\cal O}(\alpha_s^5)$ in QCD. 
P. A. Baikov, K. G. Chetyrkin and J. H. K\"uhn
hep-ph hep-th