QCD Sum Rules and the Validity of Effective Models

The consistency of effective models with QCD is investigated through the use of the QCD sum rule. Taking the potential model for the heavy quark system, we apply the method to two phenomenologically successful parameter sets, and obtain the dependences of the model parameters on the QCD scale $\Lambda$. Comparison with the expected scaling laws allows us to reject one of the two sets. The method is applicable to any model which reproduces the low lying spectra of hadronic systems.