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Related papers: Comments on Global Parton Analyses

200 papers

Parton distribution functions (PDFs) play a central role in calculations for the Large Hadron Collider (LHC). To gain a deeper understanding of the emergence and interplay of constraints on the PDFs in the global QCD analyses, it is…

Nuclear parton distributions $f_A(x,Q^2)$ are studied within a framework of the DGLAP evolution. Measurements of $F_2^A/F_2^D$ in deep inelastic $lA$ collisions, and Drell--Yan dilepton cross sections measured in $pA$ collisions are used as…

High Energy Physics - Phenomenology · Physics 2015-06-25 K. J. Eskola , V. J. Kolhinen , P. V. Ruuskanen , C. A. Salgado

We present a systematic comparison of theoretical predictions and various high-precision experimental measurements, specifically of differential cross sections performed by the LHC run II for Drell-Yan gauge boson, top-quark pair,…

In this letter we show that for observables which involve the measurement of weak charge in final states in hadronic collisions, the standard parton model picture breaks down at scales well above the weak scale due to nonfactorizable…

High Energy Physics - Phenomenology · Physics 2019-11-20 Matthew Baumgart , Ozan Erdoğan , Ira Z. Rothstein , Varun Vaidya

We address a long standing problem concerning the scale behaviour of parton densities in the low $x$, low $Q^2$ domain. We emphasize the important role of absorptive corrections at low $x$ and use knowledge of diffractive deep inelastic…

High Energy Physics - Phenomenology · Physics 2019-01-30 M. R. Pelicer , E. G. de Oliveira , A. D. Martin , M. G. Ryskin

Predictions for the difference of proton-antiproton and proton-proton cross sections in the heavy quark production within LO DGLAP analysis together with the $ln^2x$ terms resummation are presented. An important role of the double…

High Energy Physics - Phenomenology · Physics 2014-11-17 Dorota Kotlorz , Andrzej Kotlorz

In this paper I show that it is possible to use Regge theory to constrain the initial parton distribution functions of a global DGLAP fit. In this approach, both quarks and gluons have the same high-energy behaviour which may also be used…

High Energy Physics - Phenomenology · Physics 2014-11-17 Gregory Soyez

We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology at LO and NNLO in perturbative QCD, thereby generalizing to these orders the NNPDF2.1 NLO parton…

The HERA luminosity upgrade is expected to provide statistically significant measurements of the proton structure functions at 0.5<x<0.7 and very high Q2 (Q2>>M_{Z}^2). The behaviour of the parton densities (PDFs) in this high x, Q2 regime…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Caldwell , S. Paganis , F. Sciulli

We investigate the evolution of parton densities at small values of the momentum fraction, x, by including resummed anomalous dimensions in the renormalization group equations. The resummation takes into account the leading-logarithmic…

High Energy Physics - Phenomenology · Physics 2016-09-01 R. K. Ellis , F. Hautmann , B. R. Webber

We compute double-logarithmically enhanced corrections to $\widehat{q}$ at relative order $O(g^2)$ in the setting of a weakly coupled quark-gluon plasma, observing how the thermal scale affects the region of phase space, which gives rise to…

High Energy Physics - Phenomenology · Physics 2023-08-01 Eamonn Weitz

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

Measurement at Hadron colliders of neutral- and charged-current Drell-Yan production provide essential constraints in the determination of parton distribution functions. Experimentally, they have reached percent level precision, challenging…

We present numerical studies of the leading non-linear corrections to the DGLAP evolution equations of parton distribution functions (PDFs) resulting from gluon recombination, which reduce the pace of evolution at small momentum fractions…

High Energy Physics - Phenomenology · Physics 2024-06-21 Pit Duwentäster , Vadim Guzey , Ilkka Helenius , Hannu Paukkunen

We show that to correctly describe the effects of the heavy-quark mass, m_h, in DGLAP evolution, it is necessary to work in the so-called `physical' scheme. In this way, we automatically obtain a smooth transition through the heavy-quark…

High Energy Physics - Phenomenology · Physics 2015-06-16 E. G. de Oliveira , A. D. Martin , M. G. Ryskin , A. G. Shuvaev

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

In this talk, we present the results from our recent global reanalysis of nuclear parton distribution functions (nPDFs), where the DGLAP-evolving nPDFs are constrained by nuclear hard process data from deep inelastic $l+A$ scattering (DIS)…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. J. Eskola , V. J. Kolhinen , H. Paukkunen , C. A. Salgado

We investigate the effect of the structure function F_L in global parton analyses of deep inelastic and related hard scattering data. We perform NLO and NNLO analyses which include the reduced cross section HERA data at high y, as well as…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. D. Martin , W. J. Stirling , R. S. Thorne

We compare double-differential normalized production cross sections for top-antitop $+ X$ hadroproduction at NNLO QCD accuracy, as obtained through a customized version of the MATRIX framework interfaced to PineAPPL, with recent data by the…

High Energy Physics - Phenomenology · Physics 2023-12-07 Maria Vittoria Garzelli , Javier Mazzitelli , Sven-Olaf Moch , Oleksandr Zenaiev

It is now widely recognized that large Bjorken $x$ data play an important role in global analyses of Parton Distribution Functions (PDFs) even at collider energies, through perturbative QCD evolution. For values of the scale of the…

High Energy Physics - Phenomenology · Physics 2017-11-16 Evan Askanazi , Simonetta Liuti