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Related papers: Polarized Parton Distribution Functions Reexamined

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We present pion and kaon parton distribution functions from a global QCD analysis of the experimental data within the framework of dynamical parton model. We use the DGLAP equations with parton-parton recombination corrections and the…

High Energy Physics - Phenomenology · Physics 2021-06-03 Chengdong Han , Gang Xie , Rong Wang , Xurong Chen

We discuss the bounds on polarized parton distributions which follow from their definition in terms of cross section asymmetries. We spell out how the bounds obtained in the naive parton model can be derived within perturbative QCD at…

High Energy Physics - Phenomenology · Physics 2023-12-14 Guido Altarelli , Stefano Forte , Giovanni Ridolfi

The spin structure functions g_1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH_3 and ND_3 targets at Jefferson…

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

Quantum statistical distributions for the partons provide a fair description of deep inelastic scattering data at $Q^2 = 3$ and $10 (GeV/c)^2$. The study of the polarized structure functions seems to suggest an alternative possible solution…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. Buccella , G. Miele , N. Tancredi

We derive the Leading-Order master equation to extract the polarized gluon distribution G(x;Q^2) = x \deltag(x;Q^2) from polarized proton structure function, g1p(x;Q^2). By using a Laplace-transform technique, we solve the master equation…

High Energy Physics - Phenomenology · Physics 2011-03-14 F. Taghavi-Shahri , A. Mirjalili , M. M. Yazdanpanah

The ratio g1/F1 has been measured over the range 0.03<x<0.6 and 0.3<Q2<10 (GeV/c)2 using deep-inelastic scattering of polarized electrons from polarized protons and deuterons. We find g1/F1 to be consistent with no Q2-dependence at fixed x…

High Energy Physics - Experiment · Physics 2008-11-26 The E143 Collaboration , K. Abe et al

Requiring the positivity and counting rule, we propose a new parametrization of the polarized parton distribution which reproduce the data well. We found that the NLO analysis is absolutely necessary to extract the correct information on…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Morii

Supposing there exists an effective charge which defines an evolution scheme for both unpolarised and polarised parton distribution functions (DFs) that is all-orders exact and using Ans\"atze for hadron-scale proton polarised valence quark…

High Energy Physics - Phenomenology · Physics 2023-08-09 Peng Cheng , Yang Yu , Hui-Yu Xing , Chen Chen , Zhu-Fang Cui , Craig D. Roberts

The spin structure function $g_1^p$ of the proton is studied in a two component framework, where the perturbative evolution of parton distributions and nonperturbative vector meson dominance model are used. We predict the $g_1^p$ asymmetric…

High Energy Physics - Phenomenology · Physics 2015-03-10 Wei Zhu , Jianhong Ruan

We perform a full next-to-leading analysis of the the available experimental data on the polarized structure function g_1 of the nucleon, and give a precise determination of its singlet axial charge together with a thorough assessment of…

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

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

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

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

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

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

We present a first QCD analysis of next-to-next-leading-order (NNLO) contributions of the spin-dependent parton distribution functions (PPDFs) in the nucleon and their uncertainties using the Jacobi polynomial approach. Having the NNLO…

High Energy Physics - Phenomenology · Physics 2016-06-24 F. Taghavi Shahri , Hamzeh Khanpour , S. Atashbar Tehrani , Z. Alizadeh Yazdi

We report on the first calculation of the structure function g_1 in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Vogt , S. Moch , M. Rogal , J. A. M. Vermaseren

Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when the target and/or quark are transversely polarized. Connections between this…

High Energy Physics - Phenomenology · Physics 2017-02-01 Matthias Burkardt

We review the theory of polarized structure functions measured in deep-inelastic lepton-nucleon scattering, focusing on the most recent developments. We concentrate on the structure function $g_1$, emphasizing the phenomenological problems…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stefano Forte
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