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Related papers: Valence Quark Spin Distribution Functions

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We employ the maximum entropy method to extract the valence quark distributions of the neutron at a low scale, \( Q_0^2 \). At this initial scale, the neutron is defined to contain only three valence quarks, with no contributions from sea…

High Energy Physics - Phenomenology · Physics 2025-12-17 Chengdong Han , Rong Wang , Xurong Chen

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

The quark model description of the hyperon nucleon forces, especially the antisymmetric spin-orbit forces, is studied from the spin-flavor SU(6) and the flavor SU(3) symmetry point of view. It is pointed out that the quark exchange…

High Energy Physics - Phenomenology · Physics 2009-10-30 Makoto Oka

Helicity-dependent generalized parton distributions of the nucleon are derived from the overlap representation of generalized parton distributions using light-cone wave functions obtained in constituent quark models. Results from two…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Boffi , B. Pasquini , M. Traini

The method for calculation of valence quark distributions at intermediate $x$ is presented. The imaginary part of the virtual photon forward scattering amplitude on the quark current with meson quantum number is considered. Initial and…

High Energy Physics - Phenomenology · Physics 2009-10-31 B. L. Ioffe , A. G. Oganesian

The helicity-dependent strange quark distribution in the proton, $\Delta s$, is calculated in a nonlocal chiral SU(3) effective field theory. The hadronic proton to meson plus octet or decuplet baryon splitting functions are derived at the…

High Energy Physics - Phenomenology · Physics 2022-05-25 Fangcheng He , Chueng-Ryong Ji , W. Melnitchouk , Y. Salamu , A. W. Thomas , P. Wang , X. G. Wang

We study the chiral-odd transversity spin-dependent quark distribution function $h_1 (x)$ of the nucleon in a constituent quark model. The twist-2 structure functions, $f_1(x)$, $g_1(x)$ and $h_1(x)$ are calculated within the diquark…

High Energy Physics - Phenomenology · Physics 2009-10-30 K. Suzuki , T. Shigetani

We discuss the general formalism for the calculation in light-cone quark models of the fully unintegrated, off-diagonal quark-quark correlator of the nucleon. The corresponding distributions in impact parameter space are the Wigner or…

High Energy Physics - Phenomenology · Physics 2011-03-10 Cédric Lorcé , Barbara Pasquini

Analysis was performed of semi-inclusive and inclusive spin asymmetries determined from the polarized deep inelastic scattering by the Spin Muon Collaboration. Combined analysis of data for polarized deuterium and hydrogen targets allows…

High Energy Physics - Experiment · Physics 2007-05-23 Wojciech Wiślicki

I review some recent developments in the study of quark flavor distributions in the nucleon, including (i) valence quark distributions and the quark-hadron duality prediction for the x -> 1 d/u ratio (ii) sea quark asymmetries and…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Melnitchouk

The mean square radius of the proton charge distribution was studied in the framework of the relativistic quasipotential quark model in assumption of the SU(6)-symmetry. It was shown that the proton charge radius is represented as function…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. P. Ilichova , S. G. Shulga

Recent theoretical studies have provided new insight into the intrinsic transverse momentum distributions of valence and sea quarks in the nucleon at a low scale. The valence quark transverse momentum distributions (q - qbar) are governed…

High Energy Physics - Phenomenology · Physics 2015-06-17 P. Schweitzer , M. Strikman , C. Weiss

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

High Energy Physics - Phenomenology · Physics 2007-05-23 Stanislaw Tatur , Jan Bartelski , Miroslaw Kurzela

We compute the helicity-dependent strange quark distribution in the proton in the framework of chiral effective theory. Starting from the most general chiral SU(3) Lagrangian that respects Lorentz and gauge invariance, we derive the…

High Energy Physics - Phenomenology · Physics 2021-01-01 X. G. Wang , Chueng-Ryong Ji , W. Melnitchouk , Y. Salamu , A. W. Thomas , P. Wang

Using continuum Schwinger function methods, a coherent set of predictions for proton, $\Lambda$ and $\Sigma^0$ distribution functions (DFs) has been made available -- both helicity dependent and unpolarised. The results and comparisons…

High Energy Physics - Phenomenology · Physics 2026-01-07 Yang Yu , Peng Cheng , Hui-Yu Xing , Daniele Binosi , Craig D. Roberts

A brief summary on the Wigner rotation effect in the understanding of the proton spin ``crisis" related with the Ellis-Jaffe sum rule violation, and on the proton-neutron isospin symmetry breaking explanation of the Gottfried sum rule…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bo-Qiang Ma

We suggest to compare the deep inelastic scattering structure functions measured in the unpolarized charged-lepton scattering off a transversely polarized proton and off a longitudinally polarized proton at larger Bjorken variable $x$, one…

High Energy Physics - Phenomenology · Physics 2012-10-30 Wei Zhu

A physical model is presented for the non-perturbative parton distributions in the nucleon. This is based on quantum fluctuations of the nucleon into baryon-meson pairs convoluted with Gaussian momentum distributions of partons in hadrons.…

High Energy Physics - Phenomenology · Physics 2019-08-14 Andreas Ekstedt , Hazhar Ghaderi , Gunnar Ingelman , Stefan Leupold

While the form factors and parton distributions provide separately the shape of the proton in coordinate and momentum spaces, a more powerful imaging of the proton structure can be obtained through phase-space distributions. Here we…

High Energy Physics - Phenomenology · Physics 2009-11-10 Xiangdong Ji

A general three quark bound state satisfying the Pauli principle, and conserving angular momentum and isospin, is used to investigate the spin structure of nucleons at high $x$. It is shown that, if a spin up quark dominates as $x$$\to$1…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jerrold Franklin