Leading Power Corrections in QCD: From Renormalons to Phenomenology

TL;DR

This paper analyzes leading $1/Q$ power corrections in QCD, focusing on infrared-safe event shapes in $e^+e^-$ annihilation. It develops a renormalon-based phenomenology that invokes a universal soft factor $E_{soft}$ multiplying observable-dependent coefficients, and connects these corrections to nonperturbative jet-mass scales through a hadronization-inspired picture. The authors compare predictions to data for several observables, identify a consistent nonperturbative scale around $\mathcal{O}(0.5 GeV)$, and discuss how this framework reconciles with and differs from alternative approaches like gluon-mass or frozen-coupling models. They also outline extensions to multi-jet configurations and the role of Sudakov resummation in high-energy regimes, arguing that a field-theoretic underpinning for near-two-jet hadronization effects emerges from renormalon physics.

Abstract

We consider $1/Q$ corrections to hard processes in QCD where Q is a large mass scale, concentrating on shape variables in $e^{+}e^{-}$ annihilation. While the evidence for such corrections can be and has been established by means of the renormalon technique, theory can be confronted with experiment only after clarifying the properties of the corresponding non-perturbative contribution. We list predictions based on the universality of the $1/Q$ terms, and compare them with the existing data. We also identify the scale of the non-perturbative contributions in terms of jet masses.