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Related papers: Polarized Antimatter in the Proton from Global QCD…

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We present the first global analysis of fragmentation functions (FFs) for light charged hadrons ($\pi^{\pm}$, $K^{\pm}$) at full next-to-next-to-leading order in Quantum Chromodynamics (QCD), incorporating world data from both…

High Energy Physics - Phenomenology · Physics 2025-07-28 Jun Gao , XiaoMin Shen , Hongxi Xing , Yuxiang Zhao , Bin Zhou

We present results for the $x$ dependence of the unpolarized, helicity, and transversity isovector quark distributions in the proton using lattice QCD, employing the method of quasi-distributions proposed by Ji in 2013. Compared to a…

High Energy Physics - Lattice · Physics 2016-09-02 Constantia Alexandrou , Krzysztof Cichy , Kyriakos Hadjiyiannakou , Karl Jansen , Fernanda Steffens , Christian Wiese

Understanding the origin of transverse single-spin asymmetries is a long-standing challenge in strong interaction physics. Recent precise measurements of the azimuthal distribution of charged pions in jets from STAR have shed new light on…

High Energy Physics - Experiment · Physics 2024-05-16 Ting Lin

We present a consistent calculation of the structure functions within a light-front constituent quark model of the nucleon. Relativistic effects and the relevance of the covariance constraints are analyzed for polarized parton…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Faccioli , F. Cano , M. Traini , V. Vento

We present a new NLO QCD analysis of the world data on inclusive polarized deep inelastic scattering. Comparing to our previous analysis: i) the values of g_A and a_8=3F-D are updated ii) the MRST'99 instead of the MRST'98 parametrization…

High Energy Physics - Phenomenology · Physics 2015-06-25 Elliot Leader , Aleksander V. Sidorov , Dimiter B. Stamenov

We present a systematic study of the proton spin structure in terms of measurable parton distributions. For a transversely-polarizedproton, we derive a polarization sum rule from the leading generalized parton distributions appearing in…

High Energy Physics - Phenomenology · Physics 2012-10-18 Xiangdong Ji , Xiaonu Xiong , Feng Yuan

We present the results of a QCD fit to global data on deep-inelastic polarised lepton-hadron scattering. We find that it is possible to fit the data with strongly broken SU(2) flavour for the polarised sea densities. This can easily be…

High Energy Physics - Phenomenology · Physics 2009-10-31 Dilip Kumar Ghosh , Sourendu Gupta , D. Indumathi

We investigate the polarized parton distribution functions (PDFs) and their uncertainties by using the world data on the spin asymmetry A_1. The uncertainties of the polarized PDFs are estimated by the Hessian method. The up and down…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , N. Saito

In this talk results from a new QCD analysis in leading (LO) and next--to--leading (NLO) order are presented. New parametrizations of the polarized quark and gluon densities are derived together with parametrizations of their fully…

High Energy Physics - Phenomenology · Physics 2009-09-29 J. Blümlein , H. Böttcher

In order to determine polarized parton distributions we have made a new NLO QCD fit using all experimental data on spin asymmetries measured in the deep inelastic scattering on different nucleon targets. The functional form of such…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Bartelski , S. Tatur

We compute the generalized parton distributions (GPDs) of valence quarks, sea quarks, and gluons in the proton using light-front wave functions obtained within the basis light-front quantization (BLFQ) framework, providing a realistic…

High Energy Physics - Phenomenology · Physics 2026-04-21 Yiping Liu , Siqi Xu , Chandan Mondal , Xingbo Zhao , James P. Vary

The main focus of the physics program at PHENIX and STAR that makes use of RHIC's polarized proton beams is to figure out how and if at all the gluons inside protons are polarized, or to put it another way, do the spin 1 gluons prefer to…

High Energy Physics - Experiment · Physics 2019-08-14 Frank Ellinghaus

In order to obtain polarised parton densities we have made next to leading order QCD fit using experimental data on deep inelastic structure functions on nucleons. This fit is compared with the updated fit to coresponding spin asymmetries.…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jan Bartelski , Stanislaw Tatur

A leading order QCD analysis of spin asymmetries in polarized deep inelastic lepton nucleon scattering is presented within the framework of the radiative parton model. Two resulting sets of plausible leading order spin dependent parton…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Gluck , E. Reya , W. Vogelsang

We present a new, comprehensive global analysis of parton-to-pion fragmentation functions at next-to-leading order accuracy in QCD. The obtained results are based on the latest experimental information on single-inclusive pion production in…

High Energy Physics - Phenomenology · Physics 2015-06-23 D. de Florian , R. Sassot , M. Epele , R. J. Hernandez-Pinto , M. Stratmann

We study parametrization of polarized parton distribution functions in the \alpha_s leading order (LO) and in the next-to-leading order (NLO). From \chi^2 fitting to the experimental data on A_1, optimum polarized distribution functions are…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Hirai , H. Kobayashi , M. Miyama

We perform a comprehensive global QCD analysis of spin-dependent parton distribution functions (PDFs), combining all available data on inclusive and semi-inclusive deep-inelastic scattering (DIS), as well as inclusive weak boson and jet…

High Energy Physics - Phenomenology · Physics 2025-12-11 C. Cocuzza , N. T. Hunt-Smith , W. Melnitchouk , N. Sato , A. W. Thomas

We propose a new formula for extracting the polarized gluon distribution $\Delta g$ in the proton from the large--$p_T$ light hadron pair production in deep inelastic semi-inclusive reactions. Though the process dominantly occurs via…

High Energy Physics - Phenomenology · Physics 2017-08-23 T. Morii , Y. -B. Dong , T. Yamanishi

Generalized parton distributions are a new type of hadronic observables which has recently stimulated great interest among theorists and experimentalists alike. Introduced to delineate the spin structure of the nucleon, the orbital angular…

High Energy Physics - Lattice · Physics 2009-11-07 Xiangdong Ji

An up-to-date global QCD analysis of high energy lepton-hadron and hadron-hadron interactions is performed to better determine the gluon and quark parton distributions in the nucleon. Improved experimental data on inclusive jet production,…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. L. Lai , J. Huston , S. Kuhlmann , J. Morfin , F. Olness , J. F. Owens , J. Pumplin , W. K. Tung