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Related papers: Factorisation schemes for proton PDFs

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We present a new regression model for the determination of parton distribution functions (PDF) using techniques inspired from deep learning projects. In the context of the NNPDF methodology, we implement a new efficient computing framework…

High Energy Physics - Phenomenology · Physics 2019-09-04 Stefano Carrazza , Juan Cruz-Martinez

Recently a new set of Parton Distribution Functions (NNPDF1.2) has been produced and released by the NNPDF Collaboration. The inclusion of dimuon data in the analysis allows a determination of the strange content of the proton with faithful…

High Energy Physics - Phenomenology · Physics 2009-07-28 Alberto Guffanti , Juan Rojo , Maria Ubiali

This note provides an interim summary of the current recommendations of the PDF4LHC working group for the use of parton distribution functions (PDFs) and of PDF uncertainties at the LHC, for cross section and cross section uncertainty…

The quasi parton distribution is a spatial correlation of quarks or gluons along the $z$ direction in a moving nucleon which enables direct lattice calculations of parton distribution functions. It can be defined with a nonperturbative…

High Energy Physics - Phenomenology · Physics 2018-03-28 Iain W. Stewart , Yong Zhao

The LHC has recently released precise measurements of the transverse momentum distribution of the Z-boson that provide a unique constraint on the structure of the proton. Theoretical developments now allow the prediction of these…

High Energy Physics - Phenomenology · Physics 2017-09-13 Radja Boughezal , Alberto Guffanti , Frank Petriello , Maria Ubiali

We study predictions from perturbative Quantum Chromodynamics (QCD) for the process pp -> H -> gamma gamma + X. In particular, we compare fully differential calculations at next-to-leading (NLO) and next-to-next-to-leading order (NNLO) in…

High Energy Physics - Phenomenology · Physics 2010-02-03 Fabian Stoeckli , Andre G. Holzner , Guenther Dissertori

We define the collinear factorization scheme, which absorbs only the collinear physics into the parton distribution functions. In order to isolate the collinear physics, we introduce a procedure to combine real and virtual corrections,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Fabio Maltoni , Thomas McElmurry , Robert Putman , Scott Willenbrock

We perform the first quantum computation of parton distribution function (PDF) with a real quantum device by calculating the PDF of the lightest positronium in the Schwinger model with IBM quantum computers. The calculation uses 10 qubits…

High Energy Physics - Lattice · Physics 2025-09-23 Jiunn-Wei Chen , Yu-Ting Chen , Ghanashyam Meher

At large values of $x$ the parton distribution functions (PDFs) of the proton are poorly constrained and there are considerable variations between different global fits. Data at such high $x$ have already been published by the ZEUS…

High Energy Physics - Experiment · Physics 2021-07-14 Ritu Aggarwal

I explain the current status of parton-distribution-function (PDF) studies and future experimental prospects on their determinations. First, unpolarized PDFs of the nucleon are introduced as a field of precision QCD physics including…

High Energy Physics - Phenomenology · Physics 2018-09-17 S. Kumano

Parton distribution functions (PDFs) are central to precision QCD phenomenology. Their Mellin moments can be computed on the lattice, but direct determinations using local operators, besides $\langle x \rangle$, face severe challenges from…

We review the latest progress in lattice QCD calculations of the partonic structure of hadrons. This structure is, in particular, described in terms of $x$-dependent distributions, the simplest of which are the standard parton distribution…

High Energy Physics - Lattice · Physics 2021-10-18 Krzysztof Cichy

A robust uncertainty estimate in global analyses of Parton Distribution Functions (PDFs) is essential at the Large Hadron Collider (LHC), especially in view of the high-precision data anticipated by experimentalists in the High-Luminosity…

High Energy Physics - Phenomenology · Physics 2026-04-14 Mark N. Costantini , Luca Mantani , James M. Moore , Maria Ubiali

We discuss a test of the generalization power of the methodology used in the determination of parton distribution functions (PDFs). The "future test" checks whether the uncertainty on PDFs, in regions in which they are not constrained by…

High Energy Physics - Phenomenology · Physics 2021-04-21 Juan Cruz-Martinez , Stefano Forte , Emanuele R. Nocera

In this talk, we review a QCD factorization based approach to extract parton distribution and correlation functions from lattice QCD calculation of single hadron matrix elements of quark-gluon operators. We argue that although the lattice…

High Energy Physics - Phenomenology · Physics 2015-06-23 Yan-Qing Ma , Jian-Wei Qiu

The factorization theorems of quantum chromodynamics (QCD) apply equally well to most simple quantum field theories that require renormalization but where direct calculations are much more straightforward. Working with these simpler…

High Energy Physics - Phenomenology · Physics 2023-05-03 F. Aslan , L. Gamberg , J. O. Gonzalez-Hernandez , T. Rainaldi , T. C. Rogers

An important limitation in current fits of parton distribution functions (PDFs) is that PDF uncertainties do not include any source of theoretical uncertainty. Here we present a general method for incorporating theoretical uncertainties…

High Energy Physics - Phenomenology · Physics 2018-10-05 R. L. Pearson , C. Voisey

We present NNPDFpol2.0, a new set of collinear helicity parton distribution functions (PDFs) of the proton based on legacy measurements of structure functions in inclusive neutral-current longitudinally polarised deep-inelastic scattering…

For a long time, lattice QCD was unable to address the $x$-dependence of partonic distributions, direct access to which is impossible in Euclidean spacetime. Recent years have brought a breakthrough for such calculations when it was…

High Energy Physics - Lattice · Physics 2022-02-16 Krzysztof Cichy

We review recent progress in the determination of the parton distribution functions (PDFs) of the proton, with emphasis on the applications for precision phenomenology at the Large Hadron Collider (LHC). First of all, we introduce the…

High Energy Physics - Phenomenology · Physics 2018-05-23 Jun Gao , Lucian Harland-Lang , Juan Rojo