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Related papers: The Nucleon Spin Problem

200 papers

The use of spin observables to study the semi-leptonic and non-leptonic weak interaction in atoms and nuclei is surveyed. In particular, the use of semi-leptonic neutral current scattering and atomic parity violation to search for physics…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. J. Musolf

Motivated by the recent measurement of proton-proton spin-correlation parameters up to 2.5 GeV laboratory energy, we investigate models for nucleon-nucleon (NN) scattering above 1 GeV. Signatures for a gradual failure of the traditional…

Nuclear Theory · Physics 2009-11-10 K. O. Eyser , R. Machleidt , W. Scobel , the EDDA Collaboration

The study of two spin asymmetries in hadron-hadron collisions probes the details of fundamental particle interactions in ways infeasible to machines with unpolarized collisions. Within reach is how the proton spin is distributed among its…

High Energy Physics - Phenomenology · Physics 2008-02-03 Glenn A. Ladinsky

We show that if the Lorentz transformation properties of diffraction are other than scalar, the $x \rightarrow 0$ behaviour of $g_1(x,Q^2)$ can grow. We compare with new data on $g_1^p$ from SMC, assess implications for sum rules and for…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. E. Close , R. G. Roberts

The workshop "The Helicity Structure of the Nucleon" (BNL June 5, 2006) was organized as part of the 2006 RHIC & AGS Users' Meeting to review the status of the spin problem and future directions. The presentations can be found at…

High Energy Physics - Phenomenology · Physics 2009-11-11 Steven D. Bass , Christine A. Aidala

The relatively small fraction of the spin of the proton carried by its quarks presents a major challenge to our understanding of the strong interaction. Traditional efforts to explore this problem have involved new and imaginative…

Nuclear Theory · Physics 2013-08-09 P. E. Shanahan , A. W. Thomas , K. Tsushima , R. D. Young , F. Myhrer

We calculate the spin dependent structure functions g_{1}(x) and g_{2}(x) of the proton and neutron. Our calculation uses the meson cloud model of nucleon structure, which has previously given a good description of the HERMES data on…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. Bissey , F. G. Cao , A. I. Signal

Following up on the plenary talk given by Ulf Mei{\ss}ner, I discuss a generalization of the concept of nucleon spin-polarizabilities in terms of multipole excitation/de-excitation and present an overview of the available theoretical…

Nuclear Theory · Physics 2017-08-23 Thomas R. Hemmert

This is a brief survey of the present state of ideas concerning the parton content of the nucleon spin after their ten-years evolution since the discovery of the EMC.

High Energy Physics - Phenomenology · Physics 2007-05-23 V. A. Petrov

The spin fractions and deep inelastic structure functions of the proton are analyzed using chiral field theory involving Goldstone bosons. A detailed comparison with recent chiral models sheds light on their successful description of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 H. J. Weber

Contents of Part 2: 11. Supersymmetric Grandunification and Fermion Masses (B. Bajc) 12. General Principles of Brane Kinematics and Dynamics (M. Pavsic) 13. Cosmological Neutrinos (G. Mangano) 14. The Problem of Mass (C.D. Froggatt) 15. How…

High Energy Physics - Phenomenology · Physics 2016-02-12 B. Bajc , M. Pavsic , G. Mangano , D. Grumiller , W. Kummer , J. T. Liu , M. Maceda , J. Madore

This is a comment on Chen et al Letter PRL,100, 232002 (2008).

General Physics · Physics 2008-07-08 S. C. Tiwari

This article is a short introduction to the general topic of quantum spin systems. After a brief sketch of the history of the subject, the standard mathematical framework for formulating problems and results in quantum spin systems is…

Mathematical Physics · Physics 2007-05-23 Bruno Nachtergaele

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

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…

We give an overview of the theory for generalized parton distributions. Topics covered are their general properties and physical interpretation, the possibility to explore the three-dimensional structure of hadrons at parton level, their…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Diehl

The spin structure of parity violating and time reversal invariance violating effects in neutron scattering is discussed. The explicit relations between these effects are presented in terms of functions nuclear spins and neutron partial…

Nuclear Theory · Physics 2018-06-20 Vladimir Gudkov , Hirohiko M. Shimizu

We provide a snapshot of Dyson-Schwinger equation applications to the theory and phenomenology of hadrons. Exact results for pseudoscalar mesons are highlighted, with details relating to the U_A(1) problem. Calculated masses of the lightest…

Nuclear Theory · Physics 2010-03-04 I. C. Cloet , A. Krassnigg , C. D. Roberts

Contents of Part 1: 1. Status of the Standard Model(P.H. Frampton), 2. Cosmological Constraints from MBA and Polarization (A. Melchiorri), 3. AdS/CFT Correspondence and Unification at About 4 TeV (P.H. Frampton), 4. New Solutions in String…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. H. Frampton , A. Melchiorri , L. Bonora , A. Borstnik Bracic , N. Mankoc Borstnik , H. B. Nielsen , C. D. Froggatt , Q. Shafi , E. Alvarez , F. Lizzi

We generalize the sum rules for the nucleon electric plus magnetic polarizability $\Sigma=\alpha+\beta$ and for the nucleon spin-polarizability $\gamma$, to virtual photons with $Q^2>0$. The dominant low energy cross sections are…

Nuclear Theory · Physics 2009-10-31 J. Edelmann , N. Kaiser , G. Piller , W. Weise