Potential NRQCD: an effective theory for heavy quarkonium

Within an effective field theory framework we study heavy-quark-antiquark s ystems with a typical distance between the heavy quark and the antiquark sm aller than 1/Lambda(QCD). A suitable definition of the potential is given w ithin this framework, while non-potential (retardation) effects are taken i nto account in a systematic way. We explore different physical systems. Mod el-independent results on the short distance behaviour of the energies of t he gluonic excitations between static quarks are obtained. Finally, we show how infrared renormalons affecting the static potential get cancelled in t he effective theory. (C) 2000 Elsevier Science B.V. All rights reserved.