Conformal mapping of the Borel plane: going beyond perturbative QCD

Understand

The power corrections in the Operator Product Expansion (OPE) of QCD correlators can be viewed mathematically as an illustration of the transseries concept, which allows to recover a function from its asymptotic divergent expansion.

• Alternatively, starting from the divergent behavior of the perturbative QCD encoded in the singularities in the Borel plane, a modified expansion can be defined by means of the conformal mapping of this plane.
• A comparison of the two approaches concerning their ability to recover nonperturbative properties of the true correlator was not explored up to now.
• In the present paper, we make a first attempt to investigate this problem.