English
Related papers

Related papers: Scale evolution of nuclear parton distributions

200 papers

We perform a global parton analysis of deep inelastic and related hard-scattering data, including ${\cal O}(\alpha_{\rm QED})$ corrections to the parton evolution. Although the quality of the fit is essentially unchanged, there are two…

High Energy Physics - Phenomenology · Physics 2010-03-25 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

We recall our recent description of quark parton densities of the proton at $Q^2=4 GeV^2$ in terms of Fermi-Dirac distributions parametrized with very few free parameters. We have also proposed some simple assumptions to relate unpolarized…

High Energy Physics - Phenomenology · Physics 2016-09-01 Claude Bourrely , Jacques Soffer

Nuclear parton distribution functions (NPDFs) are determined by a global analysis of experimental measurements on structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross section ratios \sigma_{DY}^A/\sigma_{DY}^{A'}, and their…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , T. -H. Nagai

It is shown that the latest results from the NMC (CERN) and E665 (Fermilab) groups on $F_2^A(x)/F_2^D(x)$ obtained in the shadowing region bring new evidence of the universal $A$ dependence of distortions made in a free-nucleon structure…

High Energy Physics - Phenomenology · Physics 2009-10-28 G. I. Smirnov

Starting with the interpretation of parton evolution with rapidity as a branching-diffusion process, we describe the different kinds of fluctuations of the density of partons which affect the properties of QCD scattering amplitudes at…

High Energy Physics - Phenomenology · Physics 2014-09-16 A. H. Mueller , S. Munier

Parametrization of nuclear parton distributions is investigated in the leading order of alpha_s. The parton distributions are provided at Q^2=1 GeV^2 with a number of parameters, which are determined by a chi^2 analysis of the data on…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Hirai , S. Kumano , M. Miyama

We extend the QCD Parton Model analysis using a factorized nuclear structure model incorporating individual nucleons and pairs of correlated nucleons. Our analysis of high-energy data from lepton Deep-Inelastic Scattering, Drell-Yan and W/Z…

We report current status of global analyses on nuclear parton distribution functions (NPDFs). The optimum NPDFs are determined by analyzing high-energy nuclear reaction data. Due to limited experimental measurements, antiquark modifications…

High Energy Physics - Phenomenology · Physics 2015-05-27 M. Hirai , S. Kumano , K. Saito

We present an introductory discussion of deep-inelastic lepton-proton scattering as a means to probe the substructure of the proton. A resume of QCD is given, emphasizing the running of the coupling constant and the DGLAP evolution…

High Energy Physics - Phenomenology · Physics 2010-03-25 Alan D. Martin

The relationship between the parton transverse momentum and longitudinal momentum, which is obtained by analysing the hadron tensor in the deep inelastic scattering (DIS) process, indicates that the transverse size of partons in a nucleon…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jian-Jun Yang , Guang-Lie Li

We present an updated determination of nuclear parton distributions (nPDFs) from a global NLO QCD analysis of hard processes in fixed-target lepton-nucleus and proton-nucleus together with collider proton-nucleus experiments. In addition to…

High Energy Physics - Phenomenology · Physics 2022-05-27 Rabah Abdul Khalek , Rhorry Gauld , Tommaso Giani , Emanuele R. Nocera , Tanjona R. Rabemananjara , Juan Rojo

We analyze experimental data of nuclear structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross section ratios for obtaining optimum parton distribution functions (PDFs) in nuclei. Then, uncertainties of the nuclear PDFs are estimated…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , T. -H. Nagai

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

We calculate nuclear parton distribution functions (PDFs), using the constituent quark model. We find the bounded valon distributions in a nuclear to be related to free valon distributions in a nucleon. By using improved bounded valon…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Atashbar Tehrani , Ali N. Khorramian , A. Mirjalili

We perform a global fit to the structure function F_2 measured in lepton-proton experiments at small values of Bjorken-x, x\le 0.01, for all experimentally available values of Q^2, 0.045 GeV^2\le Q^2 \le 800 GeV^2. We show that the recent…

High Energy Physics - Phenomenology · Physics 2009-09-01 J. L. Albacete , N. Armesto , J. G. Milhano , C. A. Salgado

Within the framework of generalized factorization of higher-twist contributions to semi-inclusive cross section of deeply inelastic scattering off a large nucleus, multiple parton scattering leads to an effective medium-modified…

High Energy Physics - Phenomenology · Physics 2014-11-20 Wei-tian Deng , Xin-Nian Wang

We generalize the leading twist theory of nuclear shadowing and calculate quark and gluon generalized parton distributions (GPDs) of spinless nuclei. We predict very large nuclear shadowing for nuclear GPDs. In the limit of the purely…

High Energy Physics - Phenomenology · Physics 2009-05-05 K. Goeke , V. Guzey , M. Siddikov

Optimum nuclear parton distributions are obtained by analyzing available experimental data on electron and muon deep inelastic scattering (DIS). The distributions are given at Q^2=1 GeV^2 with a number of parameters, which are determined by…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Hirai , S. Kumano , M. Miyama

We discuss results from our global QCD analyses including nuclear data off deuterium from various measurements, as well as off $\htri$ and $\hetri$ targets from the \mara{} experiment. We simultaneously determine the parton distribution…

High Energy Physics - Phenomenology · Physics 2024-10-30 S. I. Alekhin , S. A. Kulagin , R. Petti

We present a first determination of the nuclear parton distribution functions (nPDF) based on the NNPDF methodology: nNNPDF1.0. This analysis is based on neutral-current deep-inelastic structure function data and is performed up to NNLO in…

High Energy Physics - Phenomenology · Physics 2019-07-23 Rabah Abdul Khalek , Jacob J. Ethier , Juan Rojo