Matching functions for heavy particles
  We introduce matching functions as a means of summing heavy-quark logarithms to any order. Our analysis is based on Witten's approach, where heavy quarks are decoupled one at a time in a mass-independent renormalization scheme. The outcome is a generalization of the matching conditions of Bernreuther and Wetzel: we show how to derive closed formulas for summed logarithms to any order, and present explicit expressions for leading order and next-to-leading order contributions. The decoupling of heavy quarks in theories lacking asymptotic freedom is also considered. 
S.D. Bass (Innsbruck), R.J. Crewther (Adelaide, Durham), F.M. Steffens   (Mackenzie University) and A.W. Thomas (Adelaide)