English
Related papers

Related papers: The HOPPET NNLO parton evolution package

200 papers

I review recent progress in the NNPDF global analyses of parton distributions (PDFs) focusing on developments contributing to its new upcoming release: NNPDF4.0. The NNPDF4.0 determination represents unprecedented progress in three main…

High Energy Physics - Phenomenology · Physics 2021-04-20 Juan Rojo

We present the MSHT20qed set of parton distribution functions (PDFs). These are obtained from the MSHT20 global analysis via a refit including QED corrections to the DGLAP evolution at ${\cal O}(\alpha),{\cal O}(\alpha\alpha_S)$ and ${\cal…

High Energy Physics - Phenomenology · Physics 2022-02-16 T. Cridge , L. A. Harland-Lang , A. D. Martin , R. S. Thorne

I present a preliminary version of {\tt APFEL++}, a C++ rewriting of the Fortran 77 evolution code {\tt APFEL}. In this contribution I discuss the new philosophy adopted for the numerical computation of the convolutions, demonstrate the…

High Energy Physics - Phenomenology · Physics 2017-08-04 Valerio Bertone

We introduce the physical factorisation scheme, which is necessary to describe observables which are `not completely inclusive'. We derive the formulae for NLO DGLAP evolution in this scheme, and also for the `rotation' of the conventional…

High Energy Physics - Phenomenology · Physics 2015-06-17 E. G. de Oliveira , A. D. Martin , M. G. Ryskin

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 NNPDF collaboration has recently presented NNPDF3.1, a new determination of the parton distribution functions (PDFs) of the proton including a number of new data, some of which are particularly sensitive to the gluon PDF at large x. In…

High Energy Physics - Phenomenology · Physics 2019-02-25 Emanuele R. Nocera , Maria Ubiali

We present the first NNPDF full set of Parton Distribution Functions from a comprehensive DIS analysis. This approach, combining a Monte Carlo sampling of the probability measure in the space of PDFs with the use of neural networks as…

High Energy Physics - Phenomenology · Physics 2009-11-13 Maria Ubiali

We suggest a new procedure for extrapolating the parton distributions from HERA to much higher energies. The procedure suggested consists of two steps. First, we solve the non-linear evolution equation. Second, we introduce a correcting…

High Energy Physics - Phenomenology · Physics 2015-06-25 M. Lublinsky

We revisit the evolution of generalised parton distributions (GPDs) at the leading order in the strong coupling constant $\alpha_s$ for all of the twist-2 quark and gluon operators. We rederive the relevant one-loop evolution kernels,…

High Energy Physics - Phenomenology · Physics 2024-02-16 Valerio Bertone , Rafael F. del Castillo , Miguel G. Echevarria , Óscar del Río , Simone Rodini

Modern analysis on parton distribution functions (PDFs) requires calculations of the log-likelihood functions from thousands of experimental data points, and scans of multi-dimensional parameter space with tens of degrees of freedom. In…

High Energy Physics - Phenomenology · Physics 2022-08-24 DianYu Liu , ChuanLe Sun , Jun Gao

Parton distribution functions (PDFs) with QED corrections extracted from the QED$\otimes$QCD DGLAP evolution equations in the framework of "valon" model. Our results for the PDFs with QED corrections in this phenomenological model are in…

High Energy Physics - Phenomenology · Physics 2017-10-25 Marzieh Mottaghizadeh , Fatemeh Taghavi Shahri , Parvin Eslami

We present numerical studies of the leading non-linear corrections to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations of parton distribution functions (PDFs) resulting from gluon recombination. The effect of these…

High Energy Physics - Phenomenology · Physics 2023-12-21 Pit Duwentäster , Vadim Guzey , Ilkka Helenius , Hannu Paukkunen

In global PDF analyses, parton distribution functions (PDFs) are parametrised at a fixed input scale $Q_0$ and evolved to higher scales using the DGLAP equations. Since QCD evolution is fully determined within perturbation theory, the…

High Energy Physics - Phenomenology · Physics 2025-11-13 Ivan A. Godino , Eva D. Z. Groenendijk , Tanjona R. Rabemananjara

We construct a set of parton distribution functions (PDFs) in which fixed-order NLO and NNLO calculations are supplemented with soft-gluon (threshold) resummation up to NLL and NNLL accuracy respectively, suitable for use in conjunction…

High Energy Physics - Phenomenology · Physics 2015-10-13 Marco Bonvini , Simone Marzani , Juan Rojo , Luca Rottoli , Maria Ubiali , Richard D. Ball , Valerio Bertone , Stefano Carrazza , Nathan P. Hartland

It is the central goal of our studies to describe parton fragmentation in the hot and dense medium of a quark gluon plasma (QGP). Under the assumption that the medium is not static and homogeneous, knowledge about the temporal evolution of…

High Energy Physics - Phenomenology · Physics 2015-10-20 Rohrmoser Martin , Gossiaux Pol-Bernard , Gousset Thierry , Aichelin Jörg

This report summarizes the latest developments in the CTEQ-TEA global analysis of parton distribution functions (PDFs) in the nucleon. The focus is on recent NNLO fits to high-precision LHC data at 8 and 13 TeV, including Drell-Yan, jet,…

High Energy Physics - Phenomenology · Physics 2024-11-26 A. Ablat , A. Courtoy , S. Dulat , M. Guzzi , T. J. Hobbs , T. -J. Hou , J. Huston , K. Mohan , H. -W. Lin , P. Nadolsky , I. Sitiwaldi , K. Xie , M. Yan , C. -P. Yuan

We present an improved leading-order global DGLAP analysis of nuclear parton distribution functions (nPDFs), supplementing the traditionally used data from deep inelastic lepton-nucleus scattering and Drell-Yan dilepton production in…

High Energy Physics - Phenomenology · Physics 2010-03-25 K. J. Eskola , H. Paukkunen , C. A. Salgado

We discuss the determination of the parton substructure of hadrons by casting it as a peculiar form of pattern recognition problem in which the pattern is a probability distribution, and we present the way this problem has been tackled and…

High Energy Physics - Phenomenology · Physics 2020-08-31 Stefano Forte , Stefano Carrazza

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 present a new software package designed to reduce the computational burden of hadron collider measurements in Parton Distribution Function (PDF) fits. The APFELgrid package converts interpolated weight tables provided by APPLgrid files…

High Energy Physics - Phenomenology · Physics 2017-01-04 Valerio Bertone , Stefano Carrazza , Nathan P. Hartland