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We present a technique for implementing in a fast way, and without any approximations, higher-order calculations of partonic cross sections into global analyses of parton distribution functions. The approach, which is set up in…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Stratmann , W. Vogelsang

This document describes a Fortran 95 package for carrying out DGLAP evolution and other common manipulations of parton distribution functions (PDFs). The PDFs are represented on a grid in x-space so as to avoid limitations on the functional…

High Energy Physics - Phenomenology · Physics 2010-03-25 Gavin P. Salam , Juan Rojo

Measurements of Deep Inelastic Scattering (DIS) provide a powerful tool to probe the fundamental structure of protons and other nuclei. The DIS cross sections can be expressed in terms of structure functions which are conventionally…

High Energy Physics - Phenomenology · Physics 2023-07-06 Tuomas Lappi , Heikki Mäntysaari , Hannu Paukkunen , Mirja Tevio

The estimation of probability density functions (PDF) using approximate maps is a fundamental building block in computational probability. We consider forward problems in uncertainty quantification: the inputs or the parameters of a…

Numerical Analysis · Mathematics 2022-03-28 Amir Sagiv

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 determination of the parton distribution functions (PDFs) is crucial for a complete understanding of the protons and neutrons that make most of the visible matter in the universe. Years of dedicated studies have yielded a quite precise…

High Energy Physics - Phenomenology · Physics 2018-10-02 Pia Zurita

This document is intended as a study of benchmark cross sections at the LHC (at 7 TeV) at NLO using modern parton distribution functions currently available from the 6 PDF fitting groups that have participated in this exercise. It also…

We study the cross section \sigma and Forward-Backward asymmetry A_{FB} in the process pp \to \gamma^*,Z \to \ell^+\ell^- (with \ell=e,\mu) for determinations of Parton Distribution Functions (PDFs) of the proton. We show that, once mapped…

High Energy Physics - Phenomenology · Physics 2019-03-19 E. Accomando , J. Fiaschi , F. Hautmann , S. Moretti

One of the great challenges of QCD is to determine the partonic structure of the nucleon from first principles. In this work, we provide such a determination of the flavor non-singlet ($u-d$) unpolarized parton distribution function (PDF),…

High Energy Physics - Lattice · Physics 2021-03-03 Manjunath Bhat , Krzysztof Cichy , Martha Constantinou , Aurora Scapellato

We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology: NNPDF2.0. Experimental data include deep-inelastic scattering with the combined HERA-I dataset,…

High Energy Physics - Phenomenology · Physics 2014-11-20 Richard D. Ball , Luigi Del Debbio , Stefano Forte , Alberto Guffanti , Jose I. Latorre , Juan Rojo , Maria Ubiali

A new and simple statistical approach is performed to calculate the parton distribution functions (PDFs) of the nucleon in terms of light-front kinematic variables. We do not put in any extra arbitrary parameter or corrected term by hand,…

High Energy Physics - Phenomenology · Physics 2009-03-12 Yunhua Zhang , Lijing Shao , Bo-Qiang Ma

The large-momentum effective theory (LaMET) framework has been widely used to determine the Bjorken-$x$ dependence of parton distribution functions (PDFs) in lattice-QCD hadron-structure calculations. In this proceeding, I highlighted…

High Energy Physics - Lattice · Physics 2021-10-14 Huey-Wen Lin

The electron, positron, and photon Parton Distribution Functions (PDFs) of the unpolarised electron have recently been computed at the next-to-leading logarithmic accuracy in QED, by adopting the $\overline{\rm MS}$ factorisation scheme. We…

High Energy Physics - Phenomenology · Physics 2021-12-22 Stefano Frixione

We present a comprehensive new global QCD analysis of polarized inclusive deep-inelastic scattering, including the latest high-precision data on longitudinal and transverse polarization asymmetries from Jefferson Lab and elsewhere. The…

High Energy Physics - Phenomenology · Physics 2016-04-13 Nobuo Sato , W. Melnitchouk , S. E. Kuhn , J. J. Ethier , A. Accardi

We calculate the minimal surface bounded by four-sided figures whose projection on a plane is a rectangle, starting with the bilinear interpolation and using, for smoothness, the Chebyshev polynomial expansion in our discretized numerical…

Mathematical Physics · Physics 2007-05-23 Sadataka Furui , Bilal Masud

This paper presents an algorithm to simulate Gaussian random vectors whose precision matrix can be expressed as a polynomial of a sparse matrix. This situation arises in particular when simulating Gaussian Markov random fields obtained by…

Methodology · Statistics 2020-04-07 Mike Pereira , Nicolas Desassis

In computational practice, we often encounter situations where only measurements at equally spaced points are available. Using standard polynomial interpolation in such cases can lead to highly inaccurate results due to numerical…

Numerical Analysis · Mathematics 2024-07-25 Ludovico Bruni Bruno , Francesco Dell'Accio , Wolfgang Erb , Federico Nudo

We perform a next-to-next-to-leading order (NNLO) analysis of nuclear parton distribution functions (nPDFs) using neutral current charged-lepton ($\ell ^\pm$ + nucleus) deeply inelastic scattering (DIS) data and Drell-Yan (DY) cross-section…

High Energy Physics - Phenomenology · Physics 2016-01-29 Hamzeh Khanpour , S. Atashbar Tehrani

Hessian PDF reweighting, or "profiling", has become a widely used way to study the impact of a new data set on parton distribution functions (PDFs) with Hessian error sets. The available implementations of this method have resorted to a…

High Energy Physics - Phenomenology · Physics 2019-09-27 Kari J. Eskola , Petja Paakkinen , Hannu Paukkunen

We present a new public code, FPPDF, to perform global fits of parton distribution functions (PDFs). The fitting methodology follows that implemented by the MSHT collaboration, namely applying a fixed polynomial parameterisation of the PDFs…

High Energy Physics - Phenomenology · Physics 2026-02-10 J. M. Cruz-Martinez , T. Giani , L. A. Harland-Lang