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A new generation of parton distribution functions with increased precision and quantitative estimates of uncertainties is presented. This work significantly extends previous CTEQ and other global analyses on two fronts: (i) a full treatment…

High Energy Physics - Phenomenology · Physics 2011-07-18 J. Pumplin , D. R. Stump , J. Huston , H. L. Lai , P. Nadolsky , W. K. Tung

In this study, we examine closely the impact of the post-CT18 LHC Drell-Yan data on parton distribution functions (PDFs) in the general CTEQ-TEA global analysis framework. We compare the two main theoretical predictions, the MCFM fixed…

High Energy Physics - Phenomenology · Physics 2023-06-08 Ibrahim Sitiwaldi , Keping Xie , Alim Ablat , Sayipjamal Dulat , Tie-Jiun Hou , C. - P. Yuan

The dependence of the top-quark mass measurement in top-quark production on the parton distribution functions is explored through the differential distribution of the invariant mass of the top-antitop system in top-quark pair production at…

High Energy Physics - Phenomenology · Physics 2022-03-16 Jason Gombas , Jarrett Fein , Sara Sawford , Reinhard Schwienhorst

We discuss cross sections for $tW$ production in proton-proton collisions at the LHC and at higher-energy colliders with energies of up to 100 TeV. We find that, remarkably, the soft-gluon corrections are numerically dominant even at very…

High Energy Physics - Phenomenology · Physics 2021-06-16 Nikolaos Kidonakis , Nodoka Yamanaka

We evaluate the uncertainties due to nuclear effects in global fits of proton parton distribution functions (PDFs) that utilise deep-inelastic scattering and Drell-Yan data on deuterium targets. To do this we use an iterative procedure to…

High Energy Physics - Phenomenology · Physics 2021-02-03 Richard D. Ball , Emanuele R. Nocera , Rosalyn L. Pearson

Dynamical parton densities, generated radiatively from valence-like inputs at some low resolution scale, are confronted with recent small-x data on deep inelastic and other hard scattering processes. It is shown that within theoretical…

High Energy Physics - Phenomenology · Physics 2011-09-13 M. Gl"uck , E. Reya , A. Vogt

A group theoretical procedure for parametrizing non-forward matrix elements of non-local QCD operators is introduced. The related (two-variable) distribution amplitudes are given as sum over power corrections of the double distributions.…

High Energy Physics - Phenomenology · Physics 2009-11-07 Bodo Geyer , Markus Lazar , Dieter Robaschik

We discuss the combined effect of QED and QCD corrections to the evolution of parton distributions. We extend the available knowledge of the Altarelli-Parisi splitting functions to one order higher in QED, and provide explicit expressions…

High Energy Physics - Phenomenology · Physics 2017-11-15 Daniel de Florian , German F. R. Sborlini , German Rodrigo

Deep inelastic scattering data on $F_2$ structure function obtained in the fixed-target experiments were analysed in the valence quark approximation with a next-to-next-to-leading-order accuracy. Parton distribution functions are…

High Energy Physics - Phenomenology · Physics 2017-12-19 A. V. Kotikov , V. G. Krivokhizhin , B. G. Shaikhatdenov

The momentum and helicity density distributions of the strange quark sea in the nucleon are obtained in leading order from charged-kaon production in deep-inelastic scattering on the deuteron. The distributions are extracted from…

High Energy Physics - Experiment · Physics 2008-11-26 HERMES Collaboration , A. Airapetian

Modified quark fragmentation functions in deeply inelastic $eA$ collisions and their QCD evolution equations are derived for the first time in the framework of multiple parton scattering. Induced radiation gives rise to additional terms in…

High Energy Physics - Phenomenology · Physics 2008-11-26 Xiaofeng Guo , Xin-Nian Wang

We investigate the behavior of spin-dependent parton distribution functions (PDFs) at large parton momentum fractions x in the context of global QCD analysis. We explore the constraints from existing deep-inelastic scattering data, and from…

High Energy Physics - Phenomenology · Physics 2015-06-19 P. Jimenez-Delgado , H. Avakian , W. Melnitchouk

The high-$x$ data from the ZEUS Collaboration are used to extract parton density distributions of the proton deep in the perturbative regime of QCD. The data primarily constrain the up-quark valence distribution and new results are…

High Energy Physics - Phenomenology · Physics 2023-04-19 Ritu Aggarwal , Michiel Botje , Allen Caldwell , Francesca Capel , Oliver Schulz

We investigate the effect of extending the standard MSTW parameterisation of input parton distribution functions (PDFs) using Chebyshev polynomials. We find evidence that four powers in the polynomial are sufficient for extremely high…

High Energy Physics - Phenomenology · Physics 2013-03-18 A. D. Martin , A. J. Th. M. Mathijssen , W. J. Stirling , R. S. Thorne , B. J. A. Watt , G. Watt

The parton distributions in the proton are evaluated dynamically using a nonlinear QCD evolution equation - the DGLAP equation with twist-4 (the GLR-MQ-ZSR) corrections - starting from a low scale $\mu^2$, where the nucleon consists of…

High Energy Physics - Phenomenology · Physics 2014-09-11 Xurong Chen , Jianhong Ruan , Rong Wang , Pengming Zhang , Wei Zhu

It is anticipated that hard double parton scatterings will occur frequently in the collisions of the LHC, producing interesting signals and significant backgrounds to certain single scattering processes. For double scattering processes in…

High Energy Physics - Phenomenology · Physics 2015-03-13 Jonathan R. Gaunt , W. James Stirling

We discuss the impact of eligible top-quark pair production differential cross-section measurements at the LHC with a collision energy of 13 TeV on the parton distribution functions (PDFs) of the proton as well as the impact of approximate…

High Energy Physics - Phenomenology · Physics 2024-11-04 Alim Ablat , Sayipjamal Dulat , Marco Guzzi , Tie-Jiun Hou , Nikolaos Kidonakis , Ibrahim Sitiwaldi , Alberto Tonero , Keping Xie , C. -P. Yuan

One-loop corrections to the $Z^{\prime}$ decay width are derived and analyzed in the framework of the general form of the 3-3-1 models. We identify two important sources of corrections: oblique corrections asociated to the $Z^{\prime}$…

High Energy Physics - Phenomenology · Physics 2009-11-05 R. Martinez , F. Ochoa

Using the leading twist approach to nuclear shadowing, which is based on the relationship between nuclear shadowing and diffraction on a nucleon, we calculate next-to-leading order nuclear parton distribution functions (nPDFs) and structure…

High Energy Physics - Phenomenology · Physics 2011-07-19 L. Frankfurt , V. Guzey , M. Strikman

We use an s-channel picture of hard hadronic collisions to investigate the parton distribution function for quarks at small momentum fraction x, which corresponds to very high energy scattering. We study the renormalized quark distribution…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. Hautmann , D. E. Soper
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