Perturbative RGE systematics in precision observables

TL;DR

This paper introduces a new method to estimate systematic uncertainties in QCD calculations caused by ambiguities in solving renormalisation group equations, improving the precision of collider physics predictions.

Contribution

It presents a general approach inspired by resummation techniques to quantify systematic effects in RGE solutions for various QCD observables.

Findings

Quantifies uncertainties in strong coupling evolution

Assesses impact on PDFs and TMDs

Improves precision in collider observable predictions

Abstract

QCD calculations for collider physics make use of perturbative solutions of renormalisation group equations (RGEs). Ambiguities related to these solutions can contribute significantly to systematic uncertainties of theoretical predictions for physical observables. We propose a general method to estimate these systematic effects using techniques inspired by soft-gluon and transverse-momentum resummation approaches. We first discuss the cases of the evolution of strong coupling $\alpha_s$, collinear parton-distribution functions (PDFs), and transverse-momentum-dependent distributions (TMDs). We then study the implications for precision observables in hadron-collider processes, such as the deep-inelastic scattering structure functions and the transverse-momentum distribution of the lepton pair in Drell-Yan production.