Download or read book Modeling Quark hadron Duality in Spin Observables written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We apply a model for the study of quark-hadron duality in inclusive electron scattering to the calculation of spin observables. The model is based on solving the Dirac equation numerically for a scalar confining linear potential and a vector color Coulomb potential. We qualitatively reproduce the features of quark-hadron duality for all potentials considered, and discuss the onset of scaling and duality for the responses, spin structure functions, and polarization asymmetries. Duality may be applied to gain access to kinematic regions which are hard to access in deep inelastic scattering, namely for x{sub Bj} --> 1, and we discuss which observables are most suitable for this application of duality.
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 Quark Hadron Duality written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I review recent developments in the study of quark-hadron duality in inclusive electron scattering in the resonance-scaling transition region. Results on matrix elements of twist-4 operators extracted from moments of the spin-dependent g1 structure function suggest that duality violating higher twists are small above Q2 (almost equal to) 1 GeV2. The systematics of the x dependence of local duality are analyzed within a quark model framework, and mechanisms are identified for spin-flavor symmetry breaking which underpin the behavior of structure functions at large x.
Download or read book Modeling Quark hadron Duality for Relativistic Confined Fermions written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss a model for the study of quark-hadron duality in inclusive electron scattering based on solving the Dirac equation numerically for a scalar confining linear potential and a vector color Coulomb potential. We qualitatively reproduce the features of quark-hadron duality for all potentials considered, and discuss similarities and differences to previous models that simplified the situation by treating either the quarks or all particles as scalars. We discuss the scaling results for PWIA and FSI, and the approach to scaling using the analog of the Callan-Gross relation for y-scaling.
Download or read book Testing Qcd Through Spin Observables In Nuclear Targets written by Jian-ping Chen and published by World Scientific. This book was released on 2003-01-16 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the invited talks and contributed papers presented at the workshop on “Testing QCD Through Spin Observables in Nuclear Targets”, held at the University of Virginia in April 2002.The workshop was proposed in the context of the large number of experiments that have used polarized deuterons or polarized 3He to extract information about the spin parameters of the neutron. The motivation for this workshop was to study the effects of the nuclear medium on the spin properties of the bound nucleon and to explore issues in QCD that might be resolved through spin observables in nuclear targets: What is the effect of the nuclear medium on the measured asymmetries? How have the latest results on the spin structure of the nucleon and the nucleon form factors changed our thinking? What advances are anticipated in the development of polarized targets?
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 Symmetry Breaking and Quark Hadron Duality in Structure Functions written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We identify conditions under which a summation over nucleon resonances can yield, via quark-hadron duality, parton model results for electromagnetic and neutrino structure functions at large x. While a summation over the lowest even and odd parity multiplets is sufficient to achieve duality in the symmetric quark model, a suppression of transitions to specific final states is required for more realistic cases incorporating SU(6) breaking. We outline several scenarios consistent with duality, discuss their implications for the high Q2 behavior of transition form factors, and illustrate how they can expose the patterns in the flavor-spin dependence of short-distance forces in the strong-QCD limit.
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 Quark hadron Duality in Structure Functions written by and published by . This book was released on 2004 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: I review recent developments in quark-hadron duality in inclusive electron-nucleon scattering. Matrix elements of twist-4 operators extracted from moments of the spin-dependent g1 structure function suggest that duality violating higher twists are small above Q2 ≈ 1 GeV2. The x dependence of local duality is analyzed within a quark model framework, and mechanisms are identified for spin-flavor symmetry breaking which underpin the behavior of structure functions at large x.
Download or read book Lepton Scattering Hadrons And Qcd Procs Of The Workshop written by W Melnitchouk and published by World Scientific. This book was released on 2001-10-19 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is centered on recent developments in the exploration of hadronic structure through lepton scattering, in the description of hadron physics directly from lattice QCD and non-perturbative QCD models, and in efforts to strengthen the links between these activities. Specific topics that are covered include: parton distribution functions, polarized structure functions, generalized structure functions, nuclear effects, quark-hadron duality, electromagnetic form factors, structure functions and hadron properties from lattice QCD, and QCD models based on the Dyson-Schwinger equations.
Download or read book Quark Hadron Duality and Scaling in Reduced QCD written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We introduce a generalization of 1+1 dimensional large N{sub c} QCD, which we refer to as ''reduced'' QCD, or rQCD. In this model gluons and quark momenta live in 1+1 dimensions only, but the quark spin and all other particles (leptons, and the photon) live in the full 1 + 3 dimensions. The bound states of quarks and antiquarks are identical to those originally described by 't Hooft (except that there are new transversely polarized states previously excluded), so the model is exactly soluble. However, significant differences arise when the model is applied to electromagnetic interactions. After reviewing the strongly interacting sector of the theory, we discuss deep inelastic scattering (DIS) in this model, and show that the new states with transverse polarization give the Callan-Gross relation and remove the pathological features of the original 1+1 dimensional description. We conclude that rQCD gives a satisfactory description of the phenomenology and provides a deep understanding of both duality and DIS.
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 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 Evidence for Quark hadron Duality in the Proton Spin Asymmetry A1 written by A. Airapetian and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quark Model and High Energy Collisions written by Vladimir Vladislavovich Anisovich and published by World Scientific. This book was released on 2004 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an updated version of the book published in 1985. QCD-motivated, it gives a detailed description of hadron structure and soft interactions in the additive quark model, where hadrons are regarded as composite systems of dressed quarks.In the past decade it has become clear that nonperturbative QCD, responsible for soft hadronic processes, may differ rather drastically from perturbative QCD. The understanding of nonperturbative QCD requires a detailed investigation of the experiments and the theoretical approaches. Bearing this in mind, the book has been rewritten paying special attention to the interplay of soft hadronic collisions and the quark model. It is at the crossroads of these domains that peculiar features of strong QCD reveal themselves.The book discusses constituent quarks, diquarks, the massive effective gluons and the problem of scalar isoscalar mesons. The quark-gluonium classification of meson states is also given. Experimentally observed properties of hadrons are presented together with the corresponding theoretical interpretation in the framework of the composite hadron structure.The text includes a large theoretical part, which shows how to treat composite systems (including relativistic ones) with a technique based on spectral integration. This technique provides the possibility of handling hadrons as weakly bound systems of quarks and, at the same time, takes into account confinement.Attention is focused on the composite structure revealing itself in high energy hadron collisions. Fields of applicability of the additive quark model are discussed, as is colour screening in hadronic collisions at high and superhigh energies. Along with a detailed presentation of hadron-hadron collisions, a description of hadron-nucleus collisions is given.
Download or read book The Quark Confinement Model of Hadrons written by G.V Efimov and published by CRC Press. This book was released on 1993-01-01 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling the gap in the literature on low-energy quark models, The Quark Confinement Model of Hadrons investigates confinement effects in the low-energy regions of particle physics using the methods of nonlocal quantum field theory. It also elucidates their role in describing microscopic quantities that characterize hadron-hadron interactions. The authors present a quark confinement model to describe the low-energy physics of light hadrons. Hadrons are treated as collective colorless excitations of quark-gluon interactions while the quark confinement is to be provided by averaging over gluon backgrounds. The model is shown to reproduce the low-energy relations of chiral theory in the case of null momenta and, in addition, allow the researcher to obtain more sophisticated hadron characteristics, such as slope parameters and form factors. Presenting a unified view on a number of low-energy phenomena, The Quark Confinement Model of Hadrons enables an understanding of problems related to the treatment of large distances within quantum chromodynamics.
