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Related papers: Polarized Parton Distribution Functions in the Nuc…

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Generalized parton distributions describe the distribution of partons in the transverse plane. For transversely polarized quarks and/or nucleons, these impact parameter dependent parton distributions are not axially symmetric. These…

High Energy Physics - Phenomenology · Physics 2008-11-26 Matthias Burkardt

The $Q^2$ evolution of polarised parton distributions at small $x$ is studied. Various analytic approximations are critically discussed. We compare the full evolution with that obtained from the leading-pole approximation to the splitting…

High Energy Physics - Phenomenology · Physics 2014-11-17 T. Gehrmann , W. J. Stirling

The amplitude of diffractive $\rho$ (and open quark) leptoproduction on a polarized target is calculated in the leading log approximation of pQCD using the hadron-parton duality hypothesis. The spin-spin asymmetry is expressed in terms of…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. G. Ryskin

We performed a phenomenological fit in order to get quark parton polarized distributions in the nucleon. All data on inclusive and semi-inclusive spin asymmetries measured on nucleon targets were used. We present the results for the flavour…

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

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

The first moments of the polarized valence parton distribution functions (PDFs) truncated to the wide Bjorken $x$ region $0.004<x<0.7$ are directly (without any fitting procedure) extracted in the next to leading order (NLO) QCD from both…

High Energy Physics - Phenomenology · Physics 2013-03-26 O. Yu. Shevchenko , R. R. Akhunzyanov , V. Yu. Lavrentyev

The theoretical predictions of the chiral quark soliton model for the unpolarized and longitudinally polarized structure functions of the nucleon are compared with recent high energy data. The theory is shown to explain all the…

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

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 construct a dynamical model for the parton distributions in a nucleus by perturbative evolution of input distributions from a low starting scale. These input distributions are obtained by modifications of the corresponding free nucleon…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. Indumathi , Wei Zhu

Quark and gluon distributions in the light-cone wavefunction of a high energy hadron or nucleus are calculated in the saturation regime. One loop calculations are performed explicitly using the equivalence between the parton distribution in…

High Energy Physics - Phenomenology · Physics 2011-08-17 A. H. Mueller

The quark helicity measured in polarized deep inelastic scattering is different from the quark spin in the rest frame of the nucleon. We point out that the quark spin distributions $\Delta q_{RF}(x)$ are connected with the quark helicity…

High Energy Physics - Phenomenology · Physics 2009-10-30 Bo-Qiang Ma , Ivan Schmidt , Jacques Soffer

By assuming that there is no significant intrinsic polarization of the gluon, we have computed the polarized quark contributions to the proton's spin under SU(3) flavor symmetry breaking for the polarized sea and have performed a global…

High Energy Physics - Phenomenology · Physics 2009-10-28 Chung-Yi Wu

We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting…

High Energy Physics - Phenomenology · Physics 2015-06-22 S. Moch , J. A. M. Vermaseren , A. Vogt

A QCD analysis of the nuclear parton distributions and structure functions in the NLO is performed by using the world data. By having bounded parton distributions for a nuclear with atomic number A, we can obtain the nuclear structure…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Atashbar Tehrani , Ali N. Khorramian

Recent progress in the field of spin physics of high energy particle interactions is reviewed with particular emphasis on the spin structure functions as measured in polarized deep inelastic lepton-nucleon scattering (DIS). New measurements…

High Energy Physics - Experiment · Physics 2011-07-19 Uta Stosslein

Based on a simple model which is compatible with the idea of the static quark model and the parton model, the polarized structure functions of proton and deuteron, two-spin asymmetries of $\pi ^0$ in polarized $pp$ reactions and inelastic…

High Energy Physics - Phenomenology · Physics 2007-05-23 Toshiyuki Morii

In the large momentum transfer limit, generalized parton distributions can be calculated through a QCD factorization theorem which involves perturbatively-calculable hard kernels and light-cone parton distribution amplitudes of hadrons. We…

High Energy Physics - Phenomenology · Physics 2009-11-10 Pervez Hoodbhoy , Xiangdong Ji , Feng Yuan

QCD motivated polarized parton distributions, evolved directly in x-space, are used to predict rates for prompt photon and Jet production at RHIC and HERA-N center of mass energies. Various scenarios for the polarized gluon distributions…

High Energy Physics - Phenomenology · Physics 2014-11-17 L. E. Gordon , G. P. Ramsey

After taking account of the scale dependence by means of the standard DGLAP evolution equation, the theoretical predictions of the chiral quark soliton model for the unpolarized and longitudinally polarized structure functions of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. Wakamatsu , T. Watabe

It has been suggested that parton distributions in coordinate space, so called Ioffe-time distributions, provide a more natural object for non-perturbative methods compared to the usual momentum distributions. In this paper we argue that…

High Energy Physics - Phenomenology · Physics 2009-10-28 L. Mankiewicz , T. Weigl