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Related papers: Polarized Parton Distributions in the Valon Model

200 papers

We show that two dimensional QCD can, to a good approximation, describe the hadronic structure functions measured in Deep Inelastic Scattering. We transform this theory into a new form, Quantum HadronDynamics (QHD), whose semi-classical…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. G. Rajeev

Spin-dependent parton distributions in the polarized virtual photon are investigated in QCD up to the next-to-leading order (NLO). In the case $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the mass squared of the probe (target)…

High Energy Physics - Phenomenology · Physics 2009-10-31 Ken Sasaki , Tsuneo Uematsu

Within the framework of the so-called "valon" model, we argue that a substantial part of the nucleon spin, about 40%, is carried by the polarized valence quarks. The remaining is the result of cancellations between gluon polarization and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Firooz Arash , Fatemeh Taghavi-Shahri

An updated next-to-leading order (NLO) QCD analysis of the spin asymmetries A_1^N(x,Q^2) and parton distributions delta f(x,Q^2) in longitudinally polarized deep-inelastic lepton-nucleon scattering is presented within the framework of the…

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

We review the present status of polarized structure functions measured in deep-inelastic scattering. We discuss the x and Q^2 dependence of the structure function g_1, and how it can be used to test perturbative QCD at next-to-leading order…

High Energy Physics - Phenomenology · Physics 2008-02-03 Stefano Forte

We develop simple analytic representations of the polarized quark and gluon distributions in the nucleon at low $Q^2$ which incorporate general constraints obtained from the requirements of color coherence of gluon couplings at $x \sim 0$…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stanley J. Brodsky , Matthias Burkardt , Ivan Schmidt

We investigate parton distributions in the virtual photon target, both polarized and unpolarized, up to the next-leading order (NLO) in QCD. Parton distributions can be predicted completely up to NLO, but they are…

High Energy Physics - Phenomenology · Physics 2009-10-31 Ken Sasaki , Tsuneo Uematsu

A survey is given on the present knowledge of the polarized parton distribution functions. We give an outlook for further developments desired both on the theoretical as well on the experimental side to complete the understanding of the…

High Energy Physics - Phenomenology · Physics 2007-08-13 Johannes Blümlein

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

We report global analysis results for polarized parton distribution functions in the nucleon. The optimum distributions are determined by using spin asymmetry data on polarized lepton scattering on proton, neutron, and deuteron. Their…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Hirai , S. Kumano , N. Saito

In the past year, polarized deep inelastic scattering experiments at CERN and SLAC have obtained structure function measurements off proton, neutron and deuteron targets at a level of precision never before achieved. The measurements can be…

High Energy Physics - Phenomenology · Physics 2010-04-06 T. Gehrmann , W. J. Stirling

Polarized parton distribution functions are determined by using asymmetry A_1 data from longitudinally polarized deep inelastic scattering experiments. From our \chi^2 analysis, polarized u-valence, d-valence, antiquark, and gluon…

High Energy Physics - Phenomenology · Physics 2017-08-23 M. Hirai

Valence quark distributions in pion, polarizied $\rho$ mesons and nucleon in the region of intermediate $x$ are obtained by generalizied QCD sum rules. It is shown, that polarization effects are very significant. The strong suppression of…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. G. Oganesian

Parton distribution functions give the probability to find partons (quarks and gluons) in a hadron as a function of the fraction x of the proton's momentum carried by the parton. They are conventionally defined in terms of matrix elements…

High Energy Physics - Lattice · Physics 2009-10-28 Davison E. Soper

Parton distributions in a {\it{valon}} in the next-to-leading order is used to determine the patron distributions in pion and kaon. The validity of the valon model is tested and shown that the partonic content of the valon is universal and…

High Energy Physics - Phenomenology · Physics 2009-11-10 Firooz Arash

We discuss the structure functions and the parton distributions in the virtual photon target, both polarized and unpolarized, beyond the leading order in QCD. We study the factorization-scheme dependence of the parton distributions.

High Energy Physics - Phenomenology · Physics 2009-10-31 Ken Sasaki , Tsuneo Uematsu

Parton distribution and correlation functions describe the relation between a hadron and the quarks and gluons (or collectively, the partons) within it, and carry rich information on hadron's partonic structure that cannot be calculated by…

High Energy Physics - Phenomenology · Physics 2020-01-08 Jian-Wei Qiu

We compute the Parton Distribution Functions (PDFs) of the unpolarised muon for the leptons, the photon, the light quarks, and the gluon. We discuss in detail the issues stemming from the necessity of evaluating the strong coupling constant…

High Energy Physics - Phenomenology · Physics 2023-12-14 Stefano Frixione , Giovanni Stagnitto

Parton distributions are constructed in a statistical physical picture of the nucleon. The chiral properties of QCD lead to strong relations between quarks and antiquarks distributions and the importance of the Pauli exclusion principle is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jacques Soffer

We consider distributions of unpolarized (polarized) quarks in unpolarized (polarized) hadrons. Our approach is based on QCD factorization. We begin with study of Basic factorization for the parton-hadron scattering amplitudes in the…

High Energy Physics - Phenomenology · Physics 2015-06-01 B. I. Ermolaev , M. Greco , S. I. Troyan