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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 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

A summary is given of the experimental and theoretical results presented in the working group on spin physics. New data on inclusive and semi-inclusive deep-inelastic scattering, combined with theoretical studies of the polarized…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mauro Anselmino , Gerard van der Steenhoven

The quantum statistical approach proposed more than one decade ago was used to determine the parton distributions for the proton by considering a large set of accurate Deep Inelastic Scattering experimental results. We propose to extend…

High Energy Physics - Phenomenology · Physics 2018-12-05 Claude Bourrely , Jacques Soffer

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 analyze spin dependent parton distributions consistent with the most recent measurements of the spin dependent deep inelastic scattering structure functions and obtained in the framework of the spin dilution model. Predictions for the…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. de Florian , L. N. Epele , H. Fanchiotti , C. A. Garcia Canal , R. Sassot

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

We discuss the impact of recent high-statistics RHIC data on the determination of the gluon polarization in the proton in the context of a global QCD analysis of polarized parton distributions. We find clear evidence for a non-vanishing…

High Energy Physics - Phenomenology · Physics 2014-07-09 Daniel de Florian , Rodolfo Sassot , Marco Stratmann , Werner Vogelsang

QCD suggests that gluons in the nucleon play an important role in {\it so-called} ``the proton spin problem''. In this talk, the behavior of the polarized gluon distribution in the nucleon is discussed by using the positivity condition of…

High Energy Physics - Phenomenology · Physics 2009-09-25 T. Morii , S. Tanaka , T. Yamanishi

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 present a new analysis of the helicity parton distributions of the nucleon. The analysis takes into account the available data from inclusive and semi-inclusive polarized deep inelastic scattering, as well as from polarized pp scattering…

High Energy Physics - Phenomenology · Physics 2008-11-26 Daniel de Florian , Rodolfo Sassot , Marco Stratmann , Werner Vogelsang

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

Polarized parton distribution functions are determined by using world data from the longitudinally polarized deep inelastic scattering experiments. A new parametrization of the parton distribution functions is adopted by taking into account…

High Energy Physics - Phenomenology · Physics 2014-11-17 Y. Goto , N. Hayashi , M. Hirai , H. Horikawa , S. Kumano , M. Miyama , T. Morii , N. Saito , T. -A. Shibata , E. Taniguchi , T. Yamanishi

We discuss techniques and results for the extraction of the nucleon's spin-dependent parton distributions and their uncertainties from data for polarized deep-inelastic lepton-nucleon and proton-proton scattering by means of a global QCD…

High Energy Physics - Phenomenology · Physics 2009-09-01 Daniel de Florian , Rodolfo Sassot , Marco Stratmann , Werner Vogelsang

The capabilities of a neutrino factory in the determination of polarized parton distributions from charged-current deep-inelastic scattering experiments is discussed. We present a study of the accuracy in the determination of polarized…

High Energy Physics - Phenomenology · Physics 2009-11-07 G. Ridolfi

A statistical model for the parton distributions in the nucleon has proven its efficiency in the analysis of deep inelastic scattering data, so we propose to extend this approach to the description of unpolarized fragmentation functions for…

High Energy Physics - Phenomenology · Physics 2009-11-10 Claude Bourrely , Jacques Soffer

I review recent theoretical results on polarized deep inelastic lepton nucleon scattering. Some specific issues, like $Q^2$ evolution of structure functions, the small $x$ behaviour, and the determination of polarized parton densities, are…

High Energy Physics - Phenomenology · Physics 2007-05-23 Giovanni Ridolfi

New polarized fragmentation functions are introduced and justified, in addition to those conventional ones assumed to be independent of the helicity of the parent parton. It is demonstrated that due to our present ignorance concerning these…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Glück , E. Reya

This article gives an overview over recent results on quark and gluon helicity distributions obtained in deep inelastic lepton nucleon scattering and proton proton interactions. Future experimental programs to study the nucleon structure…

High Energy Physics - Experiment · Physics 2011-09-13 Joerg Pretz