Heavy quark correlators in an instanton liquid model with perturbative corrections
Аннотация
In the present work, we consider the influence on the heavy quark correlators due to the instanton background in the framework of instanton liquid model (ILM) of QCD vacuum by taking into account also the perturbative gluon effects. For a single heavy quark, this leads to the mass shift due to the direct-instanton nonperturbative and ILM modified perturbative contributions, respectively. In the heavy quark-antiquark ($Q\overline{Q}$) sector, we obtain the potential consisting the direct instanton induced part and the one-gluon exchange (OGE) perturbative part, which is screened at large distances due to the nonperturbative dynamics. At the region of interest corresponding to the heavy quark physics, the screening effect in OGE can be well approximated by a Yukawa-type potential in terms of the dynamically generated gluon mass. A possible implication of the present studies to the phenomenology of heavy quarkonium is also discussed.