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Related papers: Nucleon longitudinal spin structure at COMPASS

200 papers

We propose new method which allows determination of the strange-sea quark spin distribution in the nucleon through measurement of various inclusive and semi-inclusive polarized deep inelastic electron- or muon-proton reactions. It is shown,…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. Grigoryan

The transverse nucleon spin can be transferred to the quarks and gluons in several ways. In the factorizing, hard scattering processes to be considered, these are parameterized at leading twist by the transversity distribution function and…

High Energy Physics - Phenomenology · Physics 2009-11-07 Daniel Boer

The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the…

High Energy Physics - Experiment · Physics 2008-11-26 COMPASS Collaboration , P. Abbon

The quantum statistical parton distributions approach proposed more than one decade ago is revisited by considering a larger set of recent and accurate Deep Inelastic Scattering (DIS) experimental results. It enables us to improve the…

High Energy Physics - Phenomenology · Physics 2015-06-22 Claude Bourrely , Jacques Soffer

We review what is currently known about the transverse spin structure of hadrons, in particular from observables that can be analyzed within a collinear framework. These effects have been around for 40 years and represent a critical test of…

High Energy Physics - Phenomenology · Physics 2016-12-21 D. Pitonyak

An overview of the SMC data taking and the polarized deep inelastic scattering experiment is given. The new data on the deuteron extend the kinematic range and have considerably reduced statistical and systematic errors. The evaluation of…

High Energy Physics - Experiment · Physics 2007-05-23 Guenter Baum

We investigate the spin structure of the nucleon in an extended Jaffe-Lipkin quark model. In addition to the conventional $3q$ structure, different $(3q)(Q\bar{Q})$ admixtures in the nucleon wavefunction are also taken into account. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bo-Qiang Ma , Ivan Schmidt , Jian-Jun Yang

We consider the effects of the deuteron spin rotation and oscillations at the matter which is proportional to the real part of the deuteron spin-dependent forward scattering amplitude. That gives a possibility of a direct measurement of…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. G. Baryshevsky , K. G. Batrakov , S. L. Cherkas

We present results of a perturbative QCD analysis of deep inelastic measurements of both the deuteron and proton structure functions. We evaluate the theoretical uncertainty associated to nuclear effects in the deuteron, and we extract…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. I. Alekhin , S. A. Kulagin , S. Liuti

We review recent progress in the understanding of the spin structure of the nucleon. For the free nucleon the issues addressed include the status of the Bjorken and Ellis-Jaffe sum-rules and the role of the axial anomaly. We outline recent…

High Energy Physics - Phenomenology · Physics 2015-06-25 A. W. Thomas

We review the theory of polarized deep inelastic scattering in light of the most recent experimental data. We discuss the nucleon spin decomposition and the Bjorken sum rule. The latter is used for extraction of…

High Energy Physics - Phenomenology · Physics 2008-02-03 John Ellis , Marek Karliner

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

The single spin asymmetries for a longitudinally polarized lepton beam or a longitudinally polarized nucleon target in semi-inclusive deep-inelastic scattering are twist-3 observables. We study these asymmetries in a simple diquark…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Metz , M. Schlegel

The measurement of transverse spin effects in semi-inclusive deep-inelastic scattering is an important part of the COMPASS physics program. From the analysis of the 2002-2004 data, new results for the transverse target spin asymmetry of…

High Energy Physics - Experiment · Physics 2008-12-18 COMPASS Collaboration , C. Schill

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

The internal structure of the nucleon is discussed within the context of QCD. Recent progress in understanding the distribution of flavor and spin in the nucleon is reviewed, and prospects for extending our knowledge of nucleon structure in…

High Energy Physics - Phenomenology · Physics 2017-08-23 W. Melnitchouk

Deep inelastic structure functions for the nucleon are obtained in a constituent quark model on the light cone. Parton model formulas are derived. The negative slope of $F_{2}^{n}/F_{2}^{p} requires attraction between scalar quark pairs.…

High Energy Physics - Phenomenology · Physics 2009-10-28 H. J. Weber

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 review the present status of polarized structure functions measured in deep-inelastic scattering. We discuss the x and Q^2 dependence of the structure function g_1, and how it can be used to test perturbative QCD at next-to-leading order…

High Energy Physics - Phenomenology · Physics 2008-02-03 Stefano Forte

We investigate polarization observables in hyperon-nucleon scattering by decomposing scattering amplitudes into spin-space tensors, where each component describes scattering by corresponding spin-dependent interactions, so that…

Nuclear Theory · Physics 2009-11-10 S. Ishikawa , M. Tanifuji , Y. Iseri , Y. Yamamoto