Download or read book Quark Hadron Duality Tests on Polarized Structure Functions Using CLAS written by Tony Forest and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Inclusive electron-nucleon scattering data from Jefferson Lab's Hall B has been analyzed to test quark-hadron duality for the polarized structure function g1(x, Q{sup 2}) over a Q{sup 2} range from 0.2 to 3.5 GeV{sup 2}/c{sup 2}. Incident polarized electron beam energies of 1.6 and 5.7 GeV were scattered by polarized {sup 15}NH{sub 3} and {sup 15}ND{sub 3} targets. The measurements of g1(x, Q{sup 2}) in the resonance region appear to be equivalent to a fit of g1(x, Q{sup 2}) in the deep inelastic scattering region at high Q{sup 2}. A quantitative test comparing the ratio of first moment in the resonance region to the first moment in the deep inelastic region is consistent with unity when Q{sup 2}> 2.0 GeV{sup 2}/c{sup 2} but substantially departs from unity when Q{sup 2}

Download or read book Proceedings of the First Workshop on Quark Hadron Duality and Transition to PQCD written by Alessandra Fantoni and published by World Scientific. This book was released on 2006 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: While perturbative QCD methods fully describe experimental results at high energies, and chiral perturbation theory is the low energy effective theory of the strong interactions, a form of duality is observed connecting these two regimes. In these intermediate kinematics, a wide variety of reactions are observed which can be described simultaneously by single particle (quark) scattering, and by exclusive resonance (hadron) scattering. The contributions in this proceedings volume discuss recent and existing results, and aim to foster current and future research, investigating the phenomenon of quark-hadron duality. This unique volume contains research work by scientists from different arenas of hadronic physics, dealing with different manifestations of quark-hadron duality. Sample Chapter(s). Chapter 1: Introductory Remarks on Duality in Lepton-Hadron Scattering (490 KB). Contents: Introduction and Review: Experimental and Theoretical Status: Duality in the Polarized Structure Functions (H P Blok); Spin Structure of the Nucleon and Aspects of Duality (Z E Meziani); Duality and Confinement: Quark Models of Duality in Electron and Neutrino Scattering (W Melnitchouk); Hadron Structure on the Back of an Envelope (A W Thomas et al.); Spin-Flavor Decomposition and in Polarized Semi-Inclusive Deep Inelastic Scattering Experiments at Jefferson Lab (X Jiang); Duality in Photoproduction: Duality in Vector-Meson Production (A Donnachie); Onset of Scaling in Exclusive Processes (M Mirazita); Duality in Nuclei: A Partonic Picture of Jet Fragmentation in Nuclei (X-N Wang); Quark Gluon Plasma and Hadronic Gas on the Lattice (M P Lombardo); Duality in Neutrino Experiments: Neutrinos and Local Duality (F Steffens & K Tsushima); Duality and QCD: Higher Twist Effects in Polarized DIS (E Leader et al.); Highly Excited Hadrons in QCD and Beyond (M Shifman); Future Perspectives: Transverse Polarization and Quark-Hadron Duality (O V Teryaev); Research Perspectives with the Jefferson Lab (K de Jager); Perspectives with PANDA (P Gianotti); Summary Talk (P Hoyer); and other papers. Readership: Researchers, academics and lecturers in high energy, particle and nuclear physics.

Download or read book Quark hadron Duality And The Transition To Pqcd Proceedings Of The First Workshop written by Simonetta Liuti and published by World Scientific. This book was released on 2006-02-06 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: While perturbative QCD methods fully describe experimental results at high energies, and chiral perturbation theory is the low energy effective theory of the strong interactions, a form of duality is observed connecting these two regimes. In these intermediate kinematics, a wide variety of reactions are observed which can be described simultaneously by single particle (quark) scattering, and by exclusive resonance (hadron) scattering.The contributions in this proceedings volume discuss recent and existing results, and aim to foster current and future research, investigating the phenomenon of quark-hadron duality.This unique volume contains research work by scientists from different arenas of hadronic physics, dealing with different manifestations of quark-hadron duality.

Download or read book Gdh 2004 Proceedings Of The Third International Symposium On The Gerasimov drell hearn Sum Rule And Its Extensions written by Sebastian Kuhn and published by World Scientific. This book was released on 2005-02-21 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents an overview of the many new and exciting results, both theoretical and experimental, in the area of spin structure functions and sum rules at low to moderate photon virtuality Q2. It includes contributions from many leading scientists in the field worldwide.The volume covers the following topics:• recent results on the Gerasimov-Drell-Hearn (GDH) sum rule with real photons and its extensions to virtual photons• inclusive spin structure functions at low to moderate Q2 and their moments• exclusive measurements of nucleon spin structure in the resonance region• spin polarizabilities and Compton scattering• chiral perturbation theory and other low-energy limits of QCD• lattice QCD, duality, and phenomological models• nuclear effects and the GDH sum rule in nuclei• experimental techniques (polarized targets and beams)• future plans and projects

Download or read book Quark Hadron Duality in Neutron 3He Spin Structure written by and published by . This book was released on 2008 with total page 182502 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present experimental results of the first high-precision test of quark-hadron duality in the spin-structure function g_1 of the neutron and $^3$He using a polarized 3He target in the four-momentum-transfer-squared range from 0.7 to 4.0 (GeV/c)^2. Global duality is observed for the spin-structure function g_1 down to at least Q^2 = 1.8 (GeV/c)^2 in both targets. We have also formed the photon-nucleon asymmetry A_1 in the resonance region for 3He and found no strong Q^2-dependence above 2.2 (GeV/c)^2.

Download or read book Measurement of the 3He Spin Structure Functions in the Resonance Region written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the biggest challenges in the study of the nucleon structure is the understanding of the transition from partonic degrees of freedom to hadronic degrees of freedom. In 1970, Bloom and Gilman noticed that structure function data taken at SLAC in the resonance region average to the scaling curve of deep inelastic scattering (DIS). Early theoretical interpretations suggested that these two very different regimes can be linked under the condition that the quark-gluon and quark-quark interactions are suppressed. Substantial efforts are ongoing to investigate this phenomenon both experimentally and theoretically. Quark-hadron duality has been confirmed for the unpolarized structure function F2 of the proton and the deuteron using data from the experimental Hall C at Jefferson Lab (JLab). Indications of duality have been seen for the proton polarized structure function g1 and the virtual photon asymmetry A1 at JLab Hall B and HERMES. Because of the different resonance behavior, it is expected that the onset of duality for the neutron will happen at lower momentum transfer than for the proton. Now that precise spin structure data in the DIS region are available at large x, data in the resonance region are greatly needed in order to test duality in spin-dependent structure functions. The goal of experiment E01-012 was to provide such data on the neutron (3He) in the moderate momentum transfer (Q2) region, 1.0

Download or read book Evidence for Quark hadron Duality in Gamma p Helicity Cross Sections written by and published by . This book was released on 2011 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combining data on unpolarized and polarized inclusive proton structure functions, we perform the first detailed study of quark-hadron duality in individual helicity-1/2 and 3/2 virtual photoproduction cross sections. We find that duality is realized more clearly in the helicity-1/2 channel, with duality violating corrections

Download or read book Deep Inelastic Scattering written by Masahiro Kuze and published by World Scientific. This book was released on 2007 with total page 996 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings present the most up-to-date status of deep inelastic scattering (DIS) physics. Topics such as structure function measurements and phenomenology, quantum chromodynamics (QCD) studies in DIS and photoproduction, spin physics and diffractive interactions are reviewed in detail, with emphasis on those studies that push the test of QCD and the Standard Model to the limits of their present range of validity, towards both the very high and the very low four-momentum transfers in leptonproton scattering.

Download or read book Quark hadron Duality in Structure Functions written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We review recent progress in the study of quark-hadron duality in electron-nucleon structure functions. New developments include insights into the local aspects of duality obtained using truncated moments of structure functions, which allow duality-violating higher-twist contributions to be identified in individual resonance regions. Preliminary studies of pion electropro-duction have also showed the first glimpses of duality in semi-inclusive cross sections, which if confirmed would greatly expand the scope of constraining the flavor and spin dependence of parton distributions.

Download or read book Spin Structure of the Deuteron written by Nevzat Guler and published by LAP Lambert Academic Publishing. This book was released on 2013-01 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physics program with CLAS at Jefferson Lab has collected a large amount of data on the spin structure functions of the nucleon by using polarized electron beam directed on polarized NH3 and ND3 targets. In these experiments, the virtual photon asymmetry and the spin structure functions were measured with an unprecedented precision in a large kinematic range. The data help us to better understand the spin structure of the nucleon, especially in the transition region between hadronic and quark-gluon degrees of freedom. Therefore, it will be possible to put limits on quark-hadron duality, test pQCD predictions for the quark polarization at large Bjorken x, perform more precise calculations of higher-twist matrix elements in the framework of the Operator Product Expansion and get a glimpse of A1 at high x. In addition, using available proton and deuteron data together and utilizing a new unfolding technique, the spin structure functions for the neutron in the resonance region are extracted.

Download or read book Quark Hadron Duality and Nucleon Valence Structure n written by and published by . This book was released on 1999 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A newly-obtained data sample of inclusive electron-nucleon scattering from deuterium and hydrogen targets at Jefferson Lab has been analyzed for precision tests of quark-hadron duality. In all cases, duality appears to be a non-trivial dynamic property of the nucleon structure function. Assuming duality, the proton magnetic form factor is extracted from the inelastic data alone, and found to be in good agreement with the world's data. Higher twist contributions are found to be small on average, even down to Q^2 ~ 0 5 GeV^2. The investigation yields a scaling curve from duality arguments which resembles deep-inelastic neutrino-nucleus scattering data, indicating a potential sensitivity to valence and valence-like structure.

Download or read book Quark Hadron Duality in Spin Structure Functions g 1 p and g 1 d written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: New measurements of the spin structure functions of the proton and deuteron g1{sup p}(x, Q2) and g1{sup d}(x, Q2) in the nucleon resonance region are compared with extrapolations of target-mass-corrected next-to-leading-order (NLO) QCD fits to higher energy data. Averaged over the entire resonance region (W 2 GeV), the data and QCD fits are in good agreement in both magnitude and Q2 dependence for Q2 1.7 GeV2/c2. This ''global'' duality appears to result from cancellations among the prominent ''local'' resonance regions: in particular strong [sigma]{sub 3/2} contributions in the [Delta](1232) region appear to be compensated by strong [sigma]{sub 1/2} contributions in the resonance region centered on 1.5 GeV. These results are encouraging for the extension of NLO QCD fits to lower W and Q2 than have been used previously.

Download or read book Local Duality Predictions for X H 1 Structure Functions written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent data on the proton F2 structure function in the resonance region suggest that local quark-hadron duality works remarkably well for each of the low-lying resonances, including the elastic, to rather low values of Q2. The authors discuss model-independent relations between structure functions x≈1 and elastic electromagnetic form factors. The x→1 behavior of the nucleon polarization asymmetries and the neutron to proton structure function ratios is studied as a function of Q-squared using available data on the electric and magnetic form factors.

Download or read book Applications of Quark hadron Duality in F2 Structure Function written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Inclusive electron-proton and electron-deuteron inelastic cross sections have been measured at Jefferson Lab (JLab) in the resonance region, at large Bjorken x, up to 0.92, and four-momentum transfer squared Q2 up to 7.5 GeV2 in the experiment E00-116. These measurements are used to extend to larger x and Q2 precision, quantitative, studies of the phenomenon of quark-hadron duality. Our analysis confirms, both globally and locally, the apparent violation of quark-hadron duality previously observed at a Q2 of 3.5 GeV2 when resonance data are compared to structure function data created from CTEQ6M and MRST2004 parton distribution functions (PDFs). More importantly, our new data show that this discrepancy saturates by Q2 ~ 4 Gev2, becoming Q2 independent. This suggests only small violations of Q2 evolution by contributions from the higher-twist terms in the resonance region which is confirmed by our comparisons to ALEKHIN and ALLM97. We conclude that the unconstrained strength of the CTEQ6M and MRST2004 PDFs at large x is the major source of the disagreement between data and these parameterizations in the kinematic regime we study and that, in view of quark-hadron duality, properly averaged resonance region data could be used in global QCD fits to reduce PDF uncertainties at large x.

Download or read book Quark Hadron Duality in Neutron Spin Structure and G 2 Moments at Intermediate Q 2 written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Jefferson Lab experiment E01-012 measured the He-3 spin-structure functions and virtual photon asymmetries in the resonance region in the momentum transfer range 1.0

Download or read book Measuring the Sea Quark Polarization written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spin is a fundamental degree of freedom and measuring the spin structure functions of the nucleon should be a basic endeavor for hadron physics. Polarization experiments have been the domain of fixed target experiments. Over the years large transverse asymmetries have been observed where the prevailing QCD theories predicted little or no asymmetries, and conversely the latest deep inelastic scattering experiments of polarized leptons from polarized targets point to the possibility that little of the nucleon spin is carried by the valence quarks. The possibility of colliding high luminosity polarized proton beams in the Brookhaven Relativistic Heavy Ion Collider (RHIC) provides a great opportunity to extend these studies and systematically probe the spin dependent parton distributions specially to those reactions that are inaccessible to current experiments. This presentation focuses on the measurement of sea quark and possibly the strange quark polarization utilizing the approved RHIC detectors.

Download or read book Theoretical Nuclear Physics In Italy Proceedings Of The 9th Conference On Problems In Theoretical Nuclear Physics written by Sigfrido Boffi and published by World Scientific. This book was released on 2003-04-03 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 9th Conference on Problems in Theoretical Nuclear Physics was organized as part of the project “Theoretical Physics of Nuclei and Many-Body Systems” involving 17 Italian universities and sponsored by the Italian Ministry of Research and University.This volume includes the invited papers on the main subjects of the project and all the individual contributions on special topics. It reviews the work performed in the last two years by the participating Italian community of nuclear theorists. In addition, national and international perspectives are focussed by a panel on the future programmes of the large Italian laboratories and of the experimental community, as well as in a general review by A Faessler.