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Related papers: Polarized structure functions: a status report

200 papers

We investigate the possibility to draw conclusions on the sign of the spin-dependent gluon distribution, $\Delta G(x, Q^2)$, from existing polarized DIS data. The spin-dependent parton distributions $\Delta u_v, \Delta d_v, \Delta {\bar u},…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. -D. Nowak , A. V. Sidorov , M. V. Tokarev

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

I review the current status of the determination of helicity-dependent, or polarized, parton distribution functions from a comprehensive analysis of experimental data in perturbative quantum chromodynamics. I illustrate the latest…

High Energy Physics - Phenomenology · Physics 2016-03-23 Emanuele R. Nocera

We present a quark-parton model to describe polarized and unpolarized nucleon structure functions. The twist-two matrix elements for the QCD evolution analysis of lepton-hadron scattering are calculated within a light-front covariant quark…

High Energy Physics - Phenomenology · Physics 2011-04-15 Marco Traini , Pietro Faccioli , Vicente Vento

After the initial discovery of the so-called "spin crisis in the parton model" in the 1980's, a large set of polarization data in deep inelastic lepton-nucleon scattering was collected at labs like SLAC, DESY and CERN. More recently, new…

High Energy Physics - Phenomenology · Physics 2009-06-09 S. E. Kuhn , J. -P. Chen , E. Leader

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

In this paper polarized valon distribution is derived from unpolarized valon distribution. In driving polarized valon distribution some unknown parameters exist which must be determined by fitting to experimental data. Here we have used…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ali N. Khorramian , A. Mirjalili , S. Atashbar Tehrani

Deep inelastic polarized and unpolarized structure functions for a free nucleon are obtained in a modified Center-of-Mass bag model, which includes the symmetry breaking effects from spin-dependent interactions. The quark distribution…

High Energy Physics - Phenomenology · Physics 2014-11-17 X. Song , J. S. McCarthy

We discuss the determination of polarized parton distributions from a next-to-leading order analysis of recent experimental data. We extract the first moment of the polarized quark and gluon distribution and assess the corresponding…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefano Forte , Richard D. Ball , Giovanni Ridolfi

A QCD analysis of the world data on polarized deep inelastic scattering is presented in next--to--leading order, including the heavy flavor Wilson coefficient in leading order in the fixed flavor number scheme. New parameterizations are…

High Energy Physics - Phenomenology · Physics 2014-11-21 Johannes Blümlein , Helmut Böttcher

We study polarized-spin structure functions of the nucleon within the bosonized Nambu-Jona-Lasinio model where the nucleon emerges as a chiral soliton. We present the electromagnetic polarized structure functions, $g_{1}(x)$ and $g_{2}(x)$…

High Energy Physics - Phenomenology · Physics 2009-10-28 H. Weigel , L. Gamberg , H. Reinhardt

We discuss the role of the U(1) axial anomaly in the spin structure functions of the nucleon, with particular emphasis on how one might determine its x dependence in present and future deep inelastic scattering experiments. We focus on the…

High Energy Physics - Phenomenology · Physics 2010-02-17 S. D. Bass , A. W. Thomas

We calculated the polarized parton distributions in leading order approximation in QCD from valon model. Polarized structure function of the nucleon are analyzed in the polarized valon model in which a nucleon is assumed to be a bound state…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Atashbar Tehrani , Ali N. Khorramian

Quark-hadron duality is studied in a systematic way for both the unpolarized and polarized structure functions, by taking into account all the available data in the resonance region.In both cases, a detailed perturbative QCD based analysis…

High Energy Physics - Phenomenology · Physics 2009-11-11 A. Fantoni , N. Bianchi , S. Liuti

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 recall the physical features of the parton distributions in the quantum statistical approach of the nucleon, which allows to describe simultaneously, unpolarized and polarized Deep Inelastic Scattering data. Some predictions from a…

High Energy Physics - Phenomenology · Physics 2015-05-27 Jacques Soffer

We discuss perturbative evolution of the polarized structure function g_1 in the (x,Q^2) plane, with special regard to the small-x region. We determine g_1 in terms of polarized quark and gluon distributions using coefficient functions to…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. D. Ball , S. Forte , G. Ridolfi

We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA, including statistical errors, and discuss systematic uncertainties. We…

High Energy Physics - Phenomenology · Physics 2007-05-23 Richard D. Ball , Abhay Deshpande , Stefano Forte , Vernon W. Hughes , Jechiel Lichtenstadt , Giovanni Ridolfi

The twist 2 and twist 3 contributions of the polarized deep-inelastic structure functions are calculated both for neutral and charged current interactions using the operator product expansion in lowest order in QCD. The relations between…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Blümlein , N. Kochelev

We investigate impact of $\pi^0$-production data at Relativistic Heavy Ion Collider (RHIC) and future E07-011 experiment for the structure function $g_1$ of the deuteron at the Thomas Jefferson National Accelerator Facility (JLab) on…

High Energy Physics - Phenomenology · Physics 2009-11-13 M. Hirai , S. Kumano , Asymmetry Analysis Collaboration