On The Spin-Dependent Potential Between Heavy Quark And Antiquark
  A new formula for the heavy quark-antiquark spin dependent potential is given by using the techniques developed in the heavy quark effective theory. The leading logarithmic quark mass terms emerging from the loop contributions are explicitly extracted and summed up. There is no renormalization scale ambiguity in this new formula. The spin-dependent potential in the new formula is expressed in terms of three independent color-electric and color-magnetic field correlation functions, and it includes both the Eichten-Feinberg's formula and the one-loop QCD result as special cases. 
Yu-Qi Chen, Yu-Ping Kuang and Robert J. Oakes