Parton distributions and lattice QCD calculations: a community white paper
Abstract
In the framework of quantum chromodynamics (QCD), parton distribution functions (PDFs) quantify how the momentum and spin of a hadron are divided among its quark and gluon constituents. Two main approaches exist to determine PDFs. The first approach, based on QCD factorization theorems, realizes a QCD analysis of a suitable set of hard-scattering measurements, often using a variety of hadronic observables. The second approach, based on first-principle operator definitions of PDFs, uses lattice QCD to compute directly some PDF-related quantities, such as their moments. Motivated by recent progress in both approaches, in this document we present an overview of lattice-QCD and global-analysis techniques used to determine unpolarized and polarized proton PDFs and their moments. We provide benchmark numbers to validate present and future lattice-QCD calculations and we illustrate how they could be used to reduce the PDF uncertainties in current unpolarized and polarized global analyses. This document represents a first step towards establishing a common language between the two communities, to foster dialogue and to further improve our knowledge of PDFs.
Keywords
Cite
@article{arxiv.1711.07916,
title = {Parton distributions and lattice QCD calculations: a community white paper},
author = {Huey-Wen Lin and Emanuele R. Nocera and Fred Olness and Kostas Orginos and Juan Rojo and Alberto Accardi and Constantia Alexandrou and Alessandro Bacchetta and Giuseppe Bozzi and Jiunn-Wei Chen and Sara Collins and Amanda Cooper-Sarkar and Martha Constantinou and Luigi Del Debbio and Michael Engelhardt and Jeremy Green and Rajan Gupta and Lucian A. Harland-Lang and Tomomi Ishikawa and Aleksander Kusina and Keh-Fei Liu and Simonetta Liuti and Christopher Monahan and Pavel Nadolsky and Jian-Wei Qiu and Ingo Schienbein and Gerrit Schierholz and Robert S. Thorne and Werner Vogelsang and Hartmut Wittig and C. -P. Yuan and James Zanotti},
journal= {arXiv preprint arXiv:1711.07916},
year = {2018}
}
Comments
80 pages, 15 figures, 28 tables, minor typos corrected, published in Progress in Particle and Nuclear Physics