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Related papers: Spin Structure of the Proton

200 papers

Spin asymmetries of semi-inclusive cross sections for the production of positively and negatively charged hadrons have been measured in deep-inelastic scattering of polarized positrons on polarized hydrogen and 3He targets, in the kinematic…

High Energy Physics - Experiment · Physics 2008-11-26 K. Ackerstaff , The HERMES Collaboration

The main focus of the physics program at PHENIX and STAR that makes use of RHIC's polarized proton beams is to figure out how and if at all the gluons inside protons are polarized, or to put it another way, do the spin 1 gluons prefer to…

High Energy Physics - Experiment · Physics 2019-08-14 Frank Ellinghaus

We discuss techniques and results for the extraction of the nucleon's spin-dependent parton distributions and their uncertainties from data for polarized deep-inelastic lepton-nucleon and proton-proton scattering by means of a global QCD…

High Energy Physics - Phenomenology · Physics 2009-09-01 Daniel de Florian , Rodolfo Sassot , Marco Stratmann , Werner Vogelsang

We have made next to leading order QCD fit to the deep inelastic spin asymmetries on nucleons and we have determined polarised quark and gluon densities. The functional form for such distributions was inspired by the unpolarised ones given…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Bartelski , S. Tatur

We give an overview of the current status of investigations of the polarization of gluons in the nucleon. We describe some of the physics of the spin-dependent gluon parton distribution and its phenomenology in high-energy polarized…

High Energy Physics - Phenomenology · Physics 2008-11-26 Marco Stratmann , Werner Vogelsang

We discuss the impact of recent high-statistics RHIC data on the determination of the gluon polarization in the proton in the context of a global QCD analysis of polarized parton distributions. We find clear evidence for a non-vanishing…

High Energy Physics - Phenomenology · Physics 2014-07-09 Daniel de Florian , Rodolfo Sassot , Marco Stratmann , Werner Vogelsang

This article reviews our present understanding of the QCD spin structure of the proton. We first outline the proton spin puzzle and its possible resolution in QCD. We then review the present and next generation of experiments to resolve the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Steven D. Bass

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

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

The hard-gluonic contribution to the first moment of the polarized proton structure function $g_1^p(x)$ is dependent of the factorization convention chosen in defining the quark spin density and the hard cross section for photon-gluon…

High Energy Physics - Phenomenology · Physics 2009-10-28 Hai-Yang Cheng , Hung Hsiang Liu , Chung-Yi Wu

We propose new method which allows determination of the strange-sea quark spin distribution in the nucleon through measurement of various inclusive and semi-inclusive polarized deep inelastic electron- or muon-proton reactions. It is shown,…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. Grigoryan

Spin-1 hadrons contain different aspects of spin physics from the ones of the spin-1/2 nucleon because of the existence of tensor-polarized structure functions. In the charged-lepton deep inelastic scattering from a spin-1 hadron or…

High Energy Physics - Phenomenology · Physics 2026-01-27 S. Kumano

The spin structure of the proton is investigated in the framework of an extended quark potential model which in addition to the conventional $3q$--structure also takes into account $(3q)(q\bar q)$--admixtures in the proton wave function.…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Keppler , H. M. Hofmann

A fit to proton, neutron and deuteron spin asymmetries is presented and polarized parton distributions in nucleon are given. These densities have their roots in the MRS fit for unpolarized case. The integrals of polarized distributions are…

High Energy Physics - Phenomenology · Physics 2008-02-03 Jan Bartelski , Stanisław Tatur

Quark contributions to the proton spin as deduced from polarized DIS of leptons off a nucleon target, and the octet baryon magnetic moments, can be used to deduce the antiquark polarizations $\Delta_{\overline{q}}$ inside the proton. In…

High Energy Physics - Phenomenology · Physics 2015-06-25 T. P. Cheng , Ling-Fong Li

QCD suggests that gluons in the nucleon play an important role in {\it so-called} ``the proton spin problem''. In this talk, the behavior of the polarized gluon distribution in the nucleon is discussed by using the positivity condition of…

High Energy Physics - Phenomenology · Physics 2009-09-25 T. Morii , S. Tanaka , T. Yamanishi

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

After a pedagogical review of the simple constituent quark model and deep inelastic sum rules, we describe how a quark sea as produced by the emission of internal Goldstone bosons by the valence quarks can account for the observed features…

High Energy Physics - Phenomenology · Physics 2009-10-30 Ling-Fong Li , T. P. Cheng

Recent progress in the understanding of the nucleon is presented. The unpolarised structure functions are obtained with unprecedented precision from the combined H1 and ZEUS data and are used to extract proton parton distribution functions…

High Energy Physics - Experiment · Physics 2009-03-27 Cristinel Diaconu

We discuss some recent developments concerning the nucleon's helicity parton distribution functions: New preliminary data from jet production at RHIC suggest for the first time a non-vanishing polarization of gluons in the nucleon. SIDIS…

High Energy Physics - Phenomenology · Physics 2015-06-03 D. de Florian , R. Sassot , M. Stratmann , W. Vogelsang