Uncovereing thick and thin strings via renormalons

Abstract

The talk is about the power corrections in QCD. Renormalons, both infrared and ultraviolet, provide with a kind of a kinematical framework to fix exponents of the leading power corrections to various observables. Any viable dynamical framework is to reproduce this pattern of the power corrections. In this mini-review, we emphasize that a simple dynamical framework satisfying this requirement may well be provided by the strings inherent to the Abelian Higgs model. This model comes naturally into consideration within the U(1) projection of QCD which makes explicit the dual-superconductor model of the confinement. At large distances (compared to $\LQ^{-1}$) there are Abrikosov-Nielsen-Olesen strings which develop a characteristic non-perturbative transverse size of order $\LQ^{-1}$ and match in this way the infrared renormalons. At short distances there are no ANO strings but there still exist dynamical manifestations of the stringy topological condition that (external) quarks are connected by a mathematically thin line along which the vacuum is trivial. These manifestations may match ultraviolet renormalons.