On linear power corrections in certain collider observables

TL;DR

This paper investigates the presence of linear power corrections in collider observables, demonstrating their absence in inclusive measurements and providing a simplified approach to calculating non-perturbative effects.

Contribution

It proves that linear power corrections do not appear in inclusive observables and offers a simplified method to compute non-perturbative corrections.

Findings

Linear power corrections are absent in inclusive observables.

A simplified calculation method for non-perturbative corrections is proposed.

Applied to compute corrections for the C-parameter and thrust in e+e- annihilation.

Abstract

We study linear power corrections ${\cal O}(\Lambda_{\rm QCD}/Q)$ to certain collider observables. We present arguments that prove that such corrections cannot appear in observables that are inclusive with respect to QCD radiation, such as total cross sections as well as rapidity and transverse momentum distributions of color-neutral particles. Although our calculations are carried out in a simplified framework, our arguments and conclusions are applicable, with some reservations, to processes both at lepton and hadron colliders. We also show how an improved understanding of the origin of linear power corrections allows us to simplify their calculation. As an application, we compute the leading non-perturbative corrections to the $C$-parameter and the thrust in $e^+e^-$ annihilation in a generic three-jet configuration.