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Related papers: PDF at small $x$ in the non-perturbative region

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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

Parton distribution functions (PDFs) describe universal properties of bound states and allow us to calculate scattering amplitudes in processes with large momentum transfer. Calculating PDFs involves the evaluation of matrix elements with a…

High Energy Physics - Lattice · Physics 2025-02-10 Mari Carmen Bañuls , Krzysztof Cichy , C. -J. David Lin , Manuel Schneider

Accurate Standard Model predictions of proton-proton collisions are essential for interpreting the current and forthcoming experimental measurements from high-energy colliders. The quest for physics beyond the Standard Model is in fact…

High Energy Physics - Phenomenology · Physics 2025-04-09 Giacomo Magni

It has been argued from the earliest days of quantum chromodynamics (QCD) that at asymptotically small values of $x$ the parton distribution functions (PDFs) of the proton behave as $x^\alpha$, where the values of $\alpha$ can be deduced…

High Energy Physics - Phenomenology · Physics 2017-03-28 Richard D. Ball , Emanuele R. Nocera , Juan Rojo

Sets of parton distribution functions (PDFs) of the proton are reported for the leading (LO), next-to-leading (NLO) and next-to-next-to leading order (NNLO) QCD calculations. The parton distribution functions are determined with the…

I investigate the behavior of spin-dependent parton distribution functions in the regions of small and large momentum fractions $x$. I present a systematic comparison between predictions for relevant observables obtained with various models…

High Energy Physics - Phenomenology · Physics 2015-06-23 Emanuele Roberto Nocera

The detailed comprehension of momentum fraction and energy dependence of proton structure functions is among the major difficulties in high-energy physics. Perturbative quantum chromodynamics (QCD) plays as an extensive foundation for…

High Energy Physics - Phenomenology · Physics 2025-09-25 Akbari Jahan , Diptimonta Neog

The parton distribution functions (PDFs) which characterize the structure of the proton are currently one of the dominant sources of uncertainty in the predictions for most processes measured at the Large Hadron Collider (LHC). Here we…

We review basic ideas and recent developments on the determination of the parton substructure of the nucleon, in view of applications to precision hadron collider physics. We review the way information on parton distributions (PDFs) is…

High Energy Physics - Phenomenology · Physics 2015-03-17 Stefano Forte

One of the main open questions in physics is the understanding of the internal structure of the strongly interacting particles, or hadrons. It is still a challenge to describe consistently the dynamics of scattering processes and hadronic…

High Energy Physics - Phenomenology · Physics 2011-11-28 A. Courtoy

It has become apparent in recent years that it is important, notably for a range of physics studies at the Large Hadron Collider, to have accurate knowledge on the distribution of photons in the proton. We show how the photon parton…

High Energy Physics - Phenomenology · Physics 2016-12-19 Aneesh Manohar , Paolo Nason , Gavin P. Salam , Giulia Zanderighi

We present the main results of our recent papers, where we derived an analytical solution of the QCD evolution equations for parton distribution functions. The valence and non-singlet quark components satisfy the Gross-Llewellyn-Smith and…

High Energy Physics - Phenomenology · Physics 2025-10-24 A. V. Kotikov , A. V. Lipatov

Global perturbative QCD analyses, based on large data sets from e-p and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear parton…

High Energy Physics - Phenomenology · Physics 2011-04-07 Paloma Quiroga-Arias , José Guilherme Milhano , Urs Achim Wiedemann

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

Although protons are baryons with an overall vanishing lepton number, they possess a non-trivial leptonic content arising from quantum fluctuations which can be described by lepton parton distribution functions (PDFs) of the proton. These…

High Energy Physics - Phenomenology · Physics 2025-01-27 Leandro Da Rold , Anibal D. Medina , Subhojit Roy , Carlos E. M. Wagner

In this contribution we discuss the main outcomes of our studies on the so called double parton distribution functions (dPDFs), accessible quantities in high energy proton-proton and proton nucleus collisions, in double parton scattering…

High Energy Physics - Phenomenology · Physics 2020-01-08 Matteo Rinaldi

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

Double parton distribution functions (dPDF), accessible in high energy proton-proton and proton nucleus collisions, encode information on how partons inside a proton are correlated among each other and could represent a tool to explore the…

High Energy Physics - Phenomenology · Physics 2015-09-30 Matteo Rinaldi , Sergio Scopetta , Marco Traini , Vicente Vento

Parton distribution functions (PDFs) are nonperturbative objects defined by nonlocal light-cone correlations. They cannot be computed directly from Quantum Chromodynamics (QCD). Using a standard lattice QCD approach, it is possible to…

High Energy Physics - Phenomenology · Physics 2017-02-08 Alessandro Bacchetta , Marco Radici , Barbara Pasquini , Xiaonu Xiong

The description of the internal structure of hadrons is one of the main goal of QCD. At moderate energy scales, the hadronic representation succeeds to the partonic description, rendering challenging the description of the dynamics of…

High Energy Physics - Phenomenology · Physics 2014-05-27 A. Courtoy