Parton distributions confront LHC Run II data: a quantitative appraisal

TL;DR

This paper systematically compares NNLO theoretical predictions with high-precision LHC and HERA data for various processes, assessing the predictive power of different PDF sets and uncertainties to enhance precision physics at the LHC.

Contribution

It provides a comprehensive quantitative assessment of how well different PDF sets and theoretical uncertainties match high-precision collider data at NNLO accuracy.

Findings

Certain PDF sets show better agreement with data.

Uncertainties significantly impact the predictive accuracy.

Control over uncertainties is crucial for precision Standard Model measurements.

Abstract

We present a systematic comparison of theoretical predictions and various high-precision experimental measurements, specifically of differential cross sections performed by the LHC run II for Drell-Yan gauge boson, top-quark pair, single-inclusive jet and di-jet production, and by HERA for single-inclusive jet and di-jet production. Theoretical predictions are computed at next-to-next-to-leading order (NNLO) accuracy in perturbative Quantum Chromodynamics. The most widely employed sets of Parton Distribution Functions (PDFs) are used, and PDF, strong coupling, and missing higher order uncertainties are taken into account. We quantitatively assess the predictive power of each PDF set and the contribution of the different sources of experimental and theoretical uncertainty to the agreement between data and predictions. We show that control over all of these aspects is crucial to precision physics studies, such as the determination of Standard Model parameters at the LHC.