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Related papers: Polarized parton distribution functions in the val…

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We introduce a new family of Generalised Parton Distribution models able to fulfil by construction all the theoretical properties imposed by QCD. These models are built on standard Parton Distribution Functions and extended to off-forward…

New polarized fragmentation functions are introduced and justified, in addition to those conventional ones assumed to be independent of the helicity of the parent parton. It is demonstrated that due to our present ignorance concerning these…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Glück , E. Reya

Structure functions of polarized spin-1 hadrons will be measured at various accelerator facilities in the near future. Recently, transverse-momentum-dependent and collinear parton distribution functions were theoretically proposed at twist…

High Energy Physics - Phenomenology · Physics 2022-01-27 S. Kumano , Qin-Tao Song

Using QCD motivated and phenomenological considerations, we construct x- dependent polarized parton distributions, which evolve under GLAP evolution, satisfy DIS data and are within positivity constraints. Each flavor is done separately and…

High Energy Physics - Phenomenology · Physics 2014-11-17 Lionel E. Gordon , Mehrdad Goshtasbpour , Gordon P. Ramsey

The theoretical framework for a next-to-leading order QCD analysis of the spin-dependent parton densities Delta f^{gamma}(x,Q^2) of the longitudinally polarized photon and of its structure function g_1^{gamma}(x,Q^2) is reviewed in some…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Stratmann

We present the distribution of unpolarized quarks in a transversely polarized proton in three-dimensional momentum space. Our results are based on consistent extractions of the unpolarized and Sivers transverse momentum dependent parton…

High Energy Physics - Phenomenology · Physics 2022-03-04 Alessandro Bacchetta , Filippo Delcarro , Cristian Pisano , Marco Radici

We discuss the generalized parton distributions (GPDs) for unpolarized hadrons, as a continuation of our recent work on hadronic structure on the light front. We analyze the unpolarized GPDs for the light nucleon and delta, as well as…

High Energy Physics - Phenomenology · Physics 2023-05-17 Edward Shuryak , Ismail Zahed

We revisit the model for parametrization of momentum dependence of nucleon generalized parton distributions in the light of recent MRST measurements of parton distribution functions. Our parametrization method with minimum set of free…

High Energy Physics - Phenomenology · Physics 2016-12-21 Neetika Sharma

The quantum statistical parton distributions approach proposed more than one decade ago is revisited by considering a larger set of recent and accurate Deep Inelastic Scattering experimental results. It enables us to improve the description…

High Energy Physics - Phenomenology · Physics 2015-12-09 Claude Bourrely , Jacques Soffer

Generalized parton distributions (GPDs) are studied at the hadronic (nonperturbative) scale within different assumptions based on a relativistic constituent quark model. In particular, by means of a meson-cloud model we investigate the role…

High Energy Physics - Phenomenology · Physics 2009-11-11 S. Boffi , B. Pasquini , M. Traini

A brief review on the status of unpolarized parton densities and the determination of the QCD scale $\Lambda_{\rm QCD}$ from deep-inelastic scattering data is presented.

High Energy Physics - Phenomenology · Physics 2007-11-14 Johannes Blümlein

We propose a physically motivated parametrization for the unpolarized generalized parton distributions. At zero value of the skewness variable, $\zeta$, the parametrization is constrained by simultaneously fitting the experimental data on…

High Energy Physics - Phenomenology · Physics 2008-11-26 Saeed Ahmad , Heli Honkanen , Simonetta Liuti , Swadhin K. Taneja

We recall the physical features of the parton distributions in the quantum statistical approach of the nucleon, which allows to describe simultaneously, unpolarized and polarized Deep Inelastic Scattering data. Some predictions from a…

High Energy Physics - Phenomenology · Physics 2015-05-27 Jacques Soffer

We calculate the valence quark distribution functions of the $\pi$ meson using the non-relativistic chiral constituent quark model. The $\pi$ wave function is obtained by solving the two-body Schr\"odinger equation within the framework of…

High Energy Physics - Phenomenology · Physics 2023-08-21 Qian Wu , Chengdong Han , Di Qing , Wei Kou , JuJun Xie , Fan Wang , Xurong Chen

In order to obtain polarised parton densities we have made next to leading order QCD fit using experimental data on deep inelastic structure functions on nucleons. This fit is compared with the updated fit to coresponding spin asymmetries.…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jan Bartelski , Stanislaw Tatur

Generalized parton distributions (GPDs) serve as indispensable tools for the exploration of proton structure. In this study, we offer a deep learning-assisted framework for the extraction of GPDs from experimental data and the results of…

High Energy Physics - Phenomenology · Physics 2026-05-14 Zaki Panjsheeri , Simonetta Liuti

We study the polarized gluon distribution $\Delta g(x)$ in a longitudinally polarized proton. We argue that the distribution can be calculated approximately from the quark color currents found in simple quark models. The first result from…

High Energy Physics - Phenomenology · Physics 2008-11-26 Panying Chen , Xiangdong Ji

We construct a parametrization of the deep-inelastic structure function of the proton F_2 based on all available experimental information from charged lepton deep-inelastic scattering experiments. The parametrization effectively provides a…

High Energy Physics - Phenomenology · Physics 2015-06-25 The NNPDF Collaboration , Luigi Del Debbio , Stefano Forte , Jose I. Latorre , Andrea Piccione , Joan Rojo

We present exploratory studies of the proton content via unpolarized and polarized transverse-momentum-dependent gluon distributions in the proton at leading twist. We make use of an enhanced spectator-model approach to encode in our…

High Energy Physics - Phenomenology · Physics 2022-06-17 Alessandro Bacchetta , Francesco Giovanni Celiberto , Marco Radici

Using a symmetry-preserving formulation of a vector$\,\times\,$vector contact interaction (SCI) and treating the proton as a quark + interacting-diquark bound state, whose structure is obtained by solving a Poincar\'e-covariant Faddeev…

High Energy Physics - Phenomenology · Physics 2024-07-17 Yang Yu , Peng Cheng , Hui-Yu Xing , Fei Gao , Craig D. Roberts