Perturbative QCD description of jet data from LHC Run-I and Tevatron Run-II

TL;DR

This paper compares precise NNLO QCD predictions for jet production at the LHC and Tevatron, evaluating the accuracy of approximate methods and their impact on parton distribution function fits.

Contribution

It provides the first exact NNLO calculations for gluon-only channels and assesses the reliability of threshold resummation approximations in jet data analysis.

Findings

Exact NNLO predictions for gluon channels are completed.

Threshold resummation approximations are reliable in specific kinematic regions.

Numerical NNLO k-factors are provided for LHC and Tevatron analyses.

Abstract

We present a systematic comparison of jet predictions at the LHC and the Tevatron, with accuracy up to next-to-next-to-leading order (NNLO). The exact computation at NNLO is completed for the gluons-only channel, so we compare the exact predictions for this channel with an approximate prediction based on threshold resummation, in order to determine the regions where this approximation is reliable at NNLO. The kinematic regions used in this study are identical to the experimental setup used by recently published jet data from the ATLAS and CMS experiments at the LHC, and CDF and D0 experiments at the Tevatron. We study the effect of choosing different renormalisation and factorisation scales for the NNLO exact prediction and as an exercise assess their impact on a PDF fit including these corrections. Finally we provide numerical values of the NNLO k-factors relevant for the LHC and Tevatron experiments.