Parton Distribution Benchmarking with LHC Data

TL;DR

This paper compares recent NNLO parton distribution functions from multiple collaborations, analyzing their impact on LHC phenomenology and benchmarking jet production predictions to assess their agreement with experimental data.

Contribution

It provides a comprehensive comparison of NNLO PDFs from various groups, including their effects on LHC cross sections and a benchmark of jet production calculations.

Findings

Good agreement among different PDF sets at certain scales.

Quantified PDF uncertainties on Higgs production cross section.

Benchmark results for jet production codes and scale choices.

Abstract

We present a detailed comparison of the most recent sets of NNLO PDFs from the ABM, CT, HERAPDF, MSTW and NNPDF collaborations. We compare parton distributions at low and high scales and parton luminosities relevant for LHC phenomenology. We study the PDF dependence of LHC benchmark inclusive cross sections and differential distributions for electroweak boson and jet production in the cases in which the experimental covariance matrix is available. We quantify the agreement between data and theory by computing the chi2 for each data set with all the various PDFs. PDF comparisons are performed consistently for common values of the strong coupling. We also present a benchmark comparison of jet production at the LHC, comparing the results from various available codes and scale settings. Finally, we discuss the implications of the updated NNLO PDF sets for the combined PDF+alphaS uncertainty in the gluon fusion Higgs production cross section.