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We study the effect on the parton distribution functions (PDFs) from the inclusion of projected measurements in the Drell-Yan (DY) di-lepton production neutral channel of the angular coefficient associated to the $Z$-boson longitudinal…

High Energy Physics - Phenomenology · Physics 2021-10-06 Juri Fiaschi

Parton Distribution Functions (PDFs) contribute significantly to the uncertainty on the determination of the top-quark pole mass and other precision measurements at the Large Hadron Collider (LHC). It is crucial to understand these…

High Energy Physics - Phenomenology · Physics 2024-01-25 Jason P. Gombas , Reinhard Schwienhorst , Binbin Dong , Jarrett Fein

We revise the relation between Parton Distribution Functions (PDFs) and matrix elements computable from lattice QCD, focusing on the quasi-Parton Distribution Functions (qPDFs) approach. We exploit the relation between PDFs and qPDFs in the…

High Energy Physics - Phenomenology · Physics 2020-01-08 Krzysztof Cichy , Luigi Del Debbio , Tommaso Giani

Quasi parton distribution functions (QPDFs) are defined in terms of QCD fields at spacelike separations evaluated in matrix elements of hadrons moving with velocity $v$. These objects can be studied in lattice QCD. In the limit when $v$…

High Energy Physics - Phenomenology · Physics 2026-05-13 Fatma Aslan , Asli Tandogan , Peter Schweitzer

We present three new sets of next-to-leading order parton distribution functions (PDFs) determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed…

High Energy Physics - Phenomenology · Physics 2013-05-15 J. F. Owens , A. Accardi , W. Melnitchouk

The Hessian method is widely applied in the global analysis of parton distribution functions (PDFs), which uses a set of orthogonal eigenvectors to give predictions of a physical observable. Its uncertainty is estimated based on the…

High Energy Physics - Phenomenology · Physics 2025-09-12 Wenxiao Zhan , Siqi Yang , Minghui Liu , Liang Han , Daniel Stump , C. -P. Yuan

We present recent updates in the xFitter software framework for global fits of parton distribution functions in high-energy physics. Our focus is on investigating the sensitivity to Z boson couplings using the forward-backward asymmetry in…

High Energy Physics - Phenomenology · Physics 2024-08-14 Oleksandr Zenaiev

We present a new set of parton distribution functions (PDFs) based on a fully global dataset and machine learning techniques: NNPDF4.0. We expand the NNPDF3.1 determination with 44 new datasets, mostly from the LHC. We derive a novel…

We present a model-independent determination of the nuclear parton distribution functions (nPDFs) using machine learning methods and Monte Carlo techniques based on the NNPDF framework. The neutral-current deep-inelastic nuclear structure…

High Energy Physics - Phenomenology · Physics 2020-10-28 Rabah Abdul Khalek , Jacob J. Ethier , Juan Rojo , Gijs van Weelden

We present the open-source SIMUnet code, designed to fit Standard Model Effective Field Theory (SMEFT) Wilson coefficient alongside Parton Distribution Functions (PDFs) of the proton. SIMUnet can perform SMEFT global fits, as well as…

High Energy Physics - Phenomenology · Physics 2024-02-06 Mark N. Costantini , Elie Hammou , Zahari Kassabov , Maeve Madigan , Luca Mantani , Manuel Morales Alvarado , James M. Moore , Maria Ubiali

We present a systematic study of uncertainties due to parton distributions and the strong coupling on the gluon-fusion production cross section of the Standard Model Higgs at the Tevatron and LHC colliders. We compare procedures and results…

High Energy Physics - Phenomenology · Physics 2014-11-20 Federico Demartin , Stefano Forte , Elisa Mariani , Juan Rojo , Alessandro Vicini

Modern global analyses of the structure of the proton include collider measurements which probe energies well above the electroweak scale. While these provide powerful constraints on the parton distribution functions (PDFs), they are also…

High Energy Physics - Phenomenology · Physics 2019-10-02 Stefano Carrazza , Celine Degrande , Shayan Iranipour , 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. Analytic expressions of x-dependent PDFs are obtained in the whole x…

High Energy Physics - Phenomenology · Physics 2011-04-07 Lijing Shao , Yunhua Zhang , Bo-Qiang Ma

We propose a method which allows the inclusion of exclusive heavy vector-meson production data at low $x$ in future global parton analyses. As an example we perform a study within xFitter to determine the gluon parton distribution function…

High Energy Physics - Phenomenology · Physics 2025-01-29 C. A. Flett , A. D. Martin , M. G. Ryskin , T. Teubner

The determination of the $W$-boson mass through an analysis of the decay charged-lepton transverse momentum distribution has a sizable uncertainty due to the imperfect knowledge of the relevant parton distribution functions (PDFs). In this…

High Energy Physics - Phenomenology · Physics 2019-09-04 Moh'd Hussein , Joshua Isaacson , Joey Huston

In this work, we investigate the valence quark parton distribution functions (PDFs) of the pion within the light-cone quark model. The initial quark PDFs are calculated by solving the quark-quark correlation function for the pseudoscalar…

High Energy Physics - Phenomenology · Physics 2026-04-08 Hari Govind P , Satyajit Puhan , Abhishek K. P , Reetanshu Pandey , Harleen Dahiya , Arvind Kumar , Suneel Dutt

The need for accurate and precise polarised parton distribution functions (PDFs) is becoming increasingly crucial in view of the Electron-Ion Collider experimental program foreseen in the coming years. Two global PDF determinations at…

High Energy Physics - Phenomenology · Physics 2024-09-17 Amedeo Chiefa

We present next-to-next-to-leading order (NNLO) parton distribution functions (PDFs) from the CTEQ-TEA group. The CT10NNLO PDF fit is based on essentially the same global data sets used in the CT10 and CT10W NLO PDF analyses. After…

High Energy Physics - Phenomenology · Physics 2014-08-21 Jun Gao , Marco Guzzi , Joey Huston , Hung-Liang Lai , Zhao Li , Pavel Nadolsky , Jon Pumplin , Daniel Stump , C. -P. Yuan

We present the first open-source analysis of fragmentation functions (FFs) of charged pions (entitled IPM-xFitter) computed at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) accuracy in perturbative QCD using the…

Uncertainties in the parametrization of Parton Distribution Functions (PDFs) are becoming a serious limiting systematic uncertainty in Large Hadron Collider (LHC) searches for Beyond the Standard Model physics. This is especially true for…

High Energy Physics - Experiment · Physics 2019-03-13 Christopher Willis , Raymond Brock , Daniel Hayden , Tie-Jiun Hou , Joshua Isaacson , Carl Schmidt , Chien-Peng Yuan