The IR renormalons exist in all perturbation series in QCD.The issue is closed related to the non-perturbative power corrections.Unlike the case of QED,the power corrections are an important subject in perturbative QCD.For instance,a precision determination of the strong coupling constant clearly needs a correct understanding of the higher-twist e?ects.In fact,already at present,the e?ects become the dominating theoretical uncertainty in some of the data analysis[34].The framework described in this paper provides one way get the problem under control.
To summarize,we have studied in this paper the IR renormalons and1/Q2corrections in deep-inelastic sum rules.The result shows that the non-perturbative1/Q2corrections depend on speci?c choices of the regularized higher-twist operators.I have proposed to de?ne a twist-four operator for the Bjorken sum rule,which is suitable for lattice calculations. The coe?cient functions for the leading-terms can only be calculated after the higher-twist operators are de?ned.Although most of the discussions in the paper are made for the Bjorken sum rule,all the results are clearly applicable to all deep-inelastic sum rules.
I wish to thank A.Mueller for many useful discussions,comments,and suggestions.Dis-cussions with K.Johnson,W.Lin,J.Negele,B.Schreiber,U.Wiese are also acknowledged.
15

