Ultraviolet renormalon reexamined

Ultraviolet-renormalon calculus.

Ultraviolet Renormalon at All Orders

We discuss the singularity in the Borel plane of the ultraviolet renormalon due to the multiple exchanges of the all-order Gell-Man–Low effective charges. A consistent picture of the UV renormalon emerges when the effective charge is considered in all orders. Contrary to the case of the one-loop effective charge, the strength of the singularity is independent of the number of exchanges. A syste...

Non-perturbative Match of Ultraviolet Renormalon

The paper is motivated by observation of a kind of branes in the vacuum state of the lattice SU(2) gluodynamics. The branes represent two-dimensional vortices whose total area scales in physical units while the non-Abelian action diverges in the ultraviolet. We consider the question whether effects of the branes can be accommodated into the continuum theory. We demonstrate that at least in case...

Modified Renormalon

In the framework of renormalon consideration in the approximation of a large number of quark flavours, a role of the anomalous dependence of gluon propagator on the scale µ is shown. In the QCD perturbation theory, an account for the next-to-leading order term over α s is connected with the uncertainty, caused by a choice of the energy scale, determining the α s (µ 2) value, since the transitio...

Ultraviolet Renormalon Ambiguities in the Determination of α S from τ Decay

The divergent large-order behaviour of the perturbative series relevant for the determination of α S from τ decay is controlled by the leading ultraviolet (UV) renormalon. Even in the absence of the first infrared (IR) renormalon, an ambiguity of order Λ 2 /m 2 τ is introduced. We make a quantitative study of the practical implications of this ambiguity. We discuss the magnitude of UV renor-mal...