English
Related papers

Related papers: How large is the gluon polarization in the statist…

200 papers

We discuss the tremendous progress that has been towards an understanding of how the spin of the proton is distributed on its quark and gluon constituents. This is a problem that began in earnest twenty years ago with the discovery of the…

High Energy Physics - Phenomenology · Physics 2014-11-20 F. Myhrer , A. W. Thomas

Quarks and gluon, as quantum particles, are subjects to various effects that go beyond the naive parton picture and are not captured by ordinary parton densities. In this work, we investigate the twist-three parton distribution functions,…

High Energy Physics - Phenomenology · Physics 2025-11-07 Alexey Vladimirov , Guillermo Portela , Simone Rodini

We provide a semi-classical description of the inclusive gluon induced Deep Inelastic Scattering cross section in a way that accounts for the leading powers in both the Regge and Bjorken limits. Our approach thus allows a systematic…

High Energy Physics - Phenomenology · Physics 2022-04-27 Renaud Boussarie , Yacine Mehtar-Tani

We introduce generalized quark and gluon distributions in the deuteron, which can be measured in exclusive processes like deeply virtual Compton scattering and meson electroproduction. We discuss the basic properties of these distributions,…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. R. Berger , F. Cano , M. Diehl , B. Pire

This paper contains three parts relating to the nucleon spin structure in a simple picture of the nucleon: (i) The polarized gluon distribution in the proton is dynamically predicted starting from a low scale by using a nonlinear QCD…

High Energy Physics - Phenomenology · Physics 2015-10-14 Wei Zhu , Jianhong Ruan

We recall the physical features of the parton distributions in the quantum statistical approach of the nucleon. Some predictions from a next-to-leading order QCD analysis are compared to recent experimental results. We also consider their…

High Energy Physics - Phenomenology · Physics 2011-07-26 Jacques Soffer

The results of a recent next-to-leading order QCD analysis of the world data on polarized deep inelastic scattering are reported. New parameterizations are derived for the quark and gluon distributions and the value of $\alpha_s(M_z^2)$ is…

High Energy Physics - Phenomenology · Physics 2010-11-19 Johannes Blümlein , Helmut Böttcher

We briefly discuss the status of double parton scattering (DPS) on both theoretical and experimental sides and summarize the state of the naive DPS model, where the scatterers are taken completely independent. We then elaborate on some of…

High Energy Physics - Phenomenology · Physics 2015-08-12 Tomas Kasemets

Parton distributions can be defined in terms of the entropy of entanglement between the spatial region probed by deep inelastic scattering (DIS) and the rest of the proton. For very small $x$, the proton becomes a maximally entangled state.…

High Energy Physics - Phenomenology · Physics 2021-09-08 Dmitri E. Kharzeev , Eugene Levin

We briefly recall the main physical features of the parton distributions in the quantum statistical picture of the nucleon. Some predictions from a next-to-leading order QCD analysis are compared to recent experimental results.

High Energy Physics - Phenomenology · Physics 2009-12-03 Jacques Soffer

We investigate the polarized parton distribution functions (PDFs) and their uncertainties by using the world data on the spin asymmetry A_1. The uncertainties of the polarized PDFs are estimated by the Hessian method. The up and down…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , N. Saito

The nucleon spin structure is studied at COMPASS via the measurement of the spin dependent properties of deep inelastic muon-deuteron scattering. Both inclusive and semi-inclusive observables are investigated, with the emphasis put on the…

High Energy Physics - Experiment · Physics 2015-06-25 Yann Bedfer

This paper gives a pedagogical introduction to our knowledge of the spin structure of the nucleon. In particular, polarised deep inelastic lepton scattering is presented as a tool to study how the nucleon's constituents combine to generate…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michel C. Vetterli

We report on a calculation of one-loop weak corrections to polarized quark-gluon scattering and the corresponding crossed channels. Such contributions are suppressed formally by one power of alpha_s relative to W- or Z-mediated quark-quark…

High Energy Physics - Phenomenology · Physics 2009-11-07 John Ellis , Stefano Moretti , Douglas Ross

A recent global QCD analysis of jet production and other polarized scattering data has found the presence of negative solutions for the gluon helicity distribution in the proton, $\Delta g$, along with the traditional $\Delta g > 0$…

High Energy Physics - Phenomenology · Physics 2026-05-04 R. M. Whitehill , Yiyu Zhou , N. Sato , W. Melnitchouk

We derive the Leading-Order master equation to extract the polarized gluon distribution G(x;Q^2) = x \deltag(x;Q^2) from polarized proton structure function, g1p(x;Q^2). By using a Laplace-transform technique, we solve the master equation…

High Energy Physics - Phenomenology · Physics 2011-03-14 F. Taghavi-Shahri , A. Mirjalili , M. M. Yazdanpanah

We present a fit to spin asymmetries which gives polarized quark distributions. These functions are closely related to the ones given by the newest Martin, Roberts and Stirling fit for unpolarized structure functions. The integrals of…

High Energy Physics - Phenomenology · Physics 2009-10-28 Jan Bartelski , Stanisław Tatur

Optimum nuclear parton distributions are determined by an analysis of muon and electron deep inelastic scattering data. Assuming simple A dependence and polynomial functions of x and 1-x for nuclear modification of parton distributions, we…

High Energy Physics - Phenomenology · Physics 2015-06-25 M. Hirai , S. Kumano , M. Miyama

A next-to-leading order QCD analysis of spin asymmetries and structure functions in polarized deep inelastic lepton nucleon scattering is presented within the framework of the radiative parton model. A consistent NLO formulation of the…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Gluck , E. Reya , M. Stratmann , W. Vogelsang

This paper discusses a selected part of the experimental program dedicated to the study of Generalized Parton Distributions, a recently introduced concept which provides a comprehensive framework for investigations of the partonic structure…

Nuclear Experiment · Physics 2007-05-23 E. Voutier