Download or read book Orbital Angular Momentum on the Light Front and QCD Observables written by Stanley J. Brodsky and published by . This book was released on 2006 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The light-front wavefunction formalism provides a physical, but rigorous, representation for angular momentum in a relativistic quantum field theory. Each n-particle LFWF {psi}{sub n}(x{sub i}, {rvec k}{sub {perpendicular}}i, S{sub i}{sup z}) in the Fock state expansion of a hadron in QCD is frame-independent and satisfies angular momentum conservation J{sup z} = {summation}{sub i=1}{sup n} S{sub i}{sup z} + {summation}{sub i=1}{sup n-1} L{sub i}{sup z}, summed over the n - 1 independent intrinsic orbital angular momenta L{sub i}{sup z} = -i [{rvec k}{sub i}{sup x} {partial_derivative}/{partial_derivative}k{sub i}{sup y} - {rvec k}{sub i}{sup y} {partial_derivative}/{partial_derivative}k{sub i}{sup x}]. Gluons propagate with physical polarization S{sub g}{sup z} = {+-} 1 in light-cone gauge A{sup +} = 0. All of these features are illustrated by the Fock state expansion of the electron in terms of its fermion-boson components.
Download or read book The AdS CFT Correspondence and Light Front QCD written by and published by . This book was released on 2008 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: We identify an invariant light-front coordinate [zeta] which allows the separation of the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single-variable light-front Schroedinger equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. This frame-independent light-front wave equation is equivalent to the equations of motion which describe the propagation of spin-J modes on anti-de Sitter (AdS) space. Light-front holography is a remarkable feature of AdS/CFT: it allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. In principle, the model can be systematically improved by diagonalizing the full QCD light-front Hamiltonian on the AdS/QCD basis. Quark and gluon hadronization can be computed at the amplitude level by convoluting the off-shell T matrix calculated from the QCD light-front Hamiltonian with the hadronic light-front wavefunctions. We also note the distinction between static observables such as the probability distributions computed from the square of the light-front wavefunctions versus dynamical observables such as the structure functions and the leading-twist single-spin asymmetries measured in deep inelastic scattering which include the effects of initial and final-state interactions.
Download or read book Theory Of Hadrons And Light Front Qcd Proceedings Of The Fourth International Workshop On Light front Quantization And Non perturbative Dynamics written by S D Glazek and published by World Scientific. This book was released on 1995-04-26 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume includes 45 talks and reports from facilitated discussions by outstanding contributors to the theory of hadrons that cover the entire spectrum of computational strategies being developed to solve QCD.A new computational strategy for solving light-front QCD, a strategy which starts with a constituent quark model that can be solved using the weak-coupling methods of QED, is extensively reviewed.
Download or read book Twisted Photons written by Juan P. Torres and published by John Wiley & Sons. This book was released on 2011-03-31 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with applications in several areas of science and technology that make use of light which carries orbital angular momentum. In most practical scenarios, the angular momentum can be decomposed into two independent contributions: the spin angular momentum and the orbital angular momentum. The orbital contribution affords a fundamentally new degree of freedom, with fascinating and wide-spread applications. Unlike spin angular momentum, which is associated with the polarization of light, the orbital angular momentum arises as a consequence of the spatial distribution of the intensity and phase of an optical field, even down to the single photon limit. Researchers have begun to appreciate its implications for our understanding of the ways in which light and matter can interact, and its practical potential in different areas of science and technology.
Download or read book Exclusive Reactions At High Momentum Transfer Iv Proceedings Of The 4th Workshop written by Anatoly Radyushkin and published by World Scientific. This book was released on 2011-02-25 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Proceedings include talks given at the 4th Workshop on Exclusive Reactions at High Momentum Transfer at Jefferson Lab, Newport News, VA USA, the world's leading facility performing research on nuclear, hadronic and quark-gluon structure of matter. Exclusive reactions are becoming one of the major sources of information about the deep structure of the nucleons and other hadrons. The workshop focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground state and excited state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities. The topics include: generalized parton distributions, deeply virtual Compton scattering, deeply virtual meson production (DVMP), transverse structure of hadrons (TMD), hadron form factors — elastic and transition, quantum chromodynamics (perturbative, non-perturbative, lattice calculations), and physics to study at an Electron Ion Collider.
Download or read book Strong Coupling Gauge Theories in LHC Era written by H. Fukuya and published by World Scientific. This book was released on 2011 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the Workshop is to have intensive discussions on both theoretical and phenomenological aspects of strong coupling gauge theories (SCGTs), with particular emphasis on the model buildings to be tested in the LHC experiments. Dynamical issues are discussed in lattice simulations and various analytical methods. This proceedings volume is a collection of the presentations made at the Workshop by many leading scientists in the field.
Download or read book Strong Coupling Gauge Theories in LHC Era written by Hidenori Fukuya and published by World Scientific. This book was released on 2011 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the Workshop is to have intensive discussions on both theoretical and phenomenological aspects of strong coupling gauge theories (SCGTs), with particular emphasis on the model buildings to be tested in the LHC experiments. Dynamical issues are discussed in lattice simulations and various analytical methods. This proceedings volume is a collection of the presentations made at the Workshop by many leading scientists in the field.
Download or read book Testing QCD Through Spin Observables in Nuclear Targets written by Don G. Crabb and published by World Scientific. This book was released on 2003 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 Transversity from First Principles in QCD written by and published by . This book was released on 2012 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transversity observables, such as the T-odd Sivers single-spin asymmetry measured in deep inelastic lepton scattering on polarized protons and the distributions which are measured in deeply virtual Compton scattering, provide important constraints on the fundamental quark and gluon structure of the proton. In this talk I discuss the challenge of computing these observables from first principles; i.e.; quantum chromodynamics, itself. A key step is the determination of the frame-independent light-front wavefunctions (LFWFs) of hadrons - the QCD eigensolutions which are analogs of the Schroedinger wavefunctions of atomic physics. The lensing effects of initial-state and final-state interactions, acting on LFWFs with different orbital angular momentum, lead to T-odd transversity observables such as the Sivers, Collins, and Boer-Mulders distributions. The lensing effect also leads to leading-twist phenomena which break leading-twist factorization such as the breakdown of the Lam-Tung relation in Drell-Yan reactions. A similar rescattering mechanism also leads to diffractive deep inelastic scattering, as well as nuclear shadowing and non-universal antishadowing. It is thus important to distinguish 'static' structure functions, the probability distributions computed the target hadron's light-front wavefunctions, versus 'dynamical' structure functions which include the effects of initial- and final-state rescattering. I also discuss related effects such as the J = 0 fixed pole contribution which appears in the real part of the virtual Compton amplitude. AdS/QCD, together with 'Light-Front Holography', provides a simple Lorentz-invariant color-confining approximation to QCD which is successful in accounting for light-quark meson and baryon spectroscopy as well as hadronic LFWFs.
Download or read book Exclusive Reactions at High Momentum Transfer IV written by Anatoly Radyushkin and published by World Scientific. This book was released on 2011 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Proceedings include talks given at the 4th Workshop on Exclusive Reactions at High Momentum Transfer at Jefferson Lab, Newport News, VA USA, the world's leading facility performing research on nuclear, hadronic and quark-gluon structure of matter. Exclusive reactions are becoming one of the major sources of information about the deep structure of the nucleons and other hadrons. The workshop focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground state and excited state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities. The topics include: generalized parton distributions, deeply virtual Compton scattering, deeply virtual meson production (DVMP), transverse structure of hadrons (TMD), hadron form factors ? elastic and transition, quantum chromodynamics (perturbative, non-perturbative, lattice calculations), and physics to study at an Electron Ion Collider.
Download or read book Optical Angular Momentum written by L. Allen and published by CRC Press. This book was released on 2016-04-19 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spin angular momentum of photons and the associated polarization of light has been known for many years. However, it is only over the last decade or so that physically realizable laboratory light beams have been used to study the orbital angular momentum of light. In many respects, orbital and spin angular momentum behave in a similar manner, but t
Download or read book Exclusive Reactions At High Momentum Transfer Proceedings Of The International Workshop written by Anatoly Radyushkin and published by World Scientific. This book was released on 2008-03-13 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exclusive reactions are becoming one of the major sources of information about the deep structure of nucleons and other hadrons. The 2007 International Workshop held at Jefferson Lab in Newport News, Virginia, USA — the world's leading facility performing research on nuclear, hadronic and quark-gluon structure of matter — focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground-state and excited-state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities.This proceedings volume contains, in concentrated form, information about the newest developments, both theoretical and experimental, in the study of hard exclusive reactions.
Download or read book Hadron Physics written by I.J. Douglas MacGregor and published by CRC Press. This book was released on 2006-07-07 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Straddling the traditional disciplines of nuclear and particle physics, hadron physics is a vital and extremely active research area, as evidenced by a 2004 Nobel prize and new research facilities, such as that scheduled to open at CERN. Scientifically it is of vital importance in extrapolating our knowledge of quark-gluon physics at the sub-nucleon level to provide a wider perspective of strongly interacting hadrons, which make up the vast bulk of known matter in the Universe. Through detailed, pedagogical chapters contributed by key international experts, Hadron Physics maps out our contemporary knowledge of the subject. It covers both the theoretical and experimental aspects of hadron structure and properties along with a wide range of specific research topics, results, and applications. Providing a full picture of activity in the field, the book highlights three particular areas of current research: computational lattice hadron physics, the structure and dynamics of hadrons, and generalized parton distributions. It provides a solid introduction, includes background theory, and presents the current state of understanding of the subject.
Download or read book Exclusive Reactions at High Momentum Transfer written by A. V. Radyushkin and published by World Scientific. This book was released on 2008 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exclusive reactions are becoming one of the major sources of information about the deep structure of nucleons and other hadrons. The 2007 International Workshop held at Jefferson Lab in Newport News, Virginia, USA - the world's leading facility performing research on nuclear, hadronic and quark-gluon structure of matter - focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground-state and excited-state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities. This proceedings volume contains, in concentrated form, information about the newest developments, both theoretical and experimental, in the study of hard exclusive reactions.
Download or read book International Conference on Color Confinement and Hadrons in Quantum Chromodynamics written by Hideo Suganuma and published by World Scientific. This book was released on 2004 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book makes a global survey of nonperturbative aspects of quantum chromodynamics (QCD) from the viewpoints of mathematical, elementary-particle and hadron physics, including recent lattice-QCD results. It presents current, important progress in the following areas: the quark confinement mechanism, dynamical chiral-symmetry breaking, topologies in QCD (instantons, monopoles, vortices), SUSY QCD, nonperturbative methods (1/Nc, ladder QCD, AdS/CFT), QCD phase transition at finite temperature and density, quark-gluon plasma, and so on. For recent topics, the book also includes the experimental discovery of the penta-quark particle, the newest information on the QGP creation experiments, and theoretical progress on the baryonic three-quark potential and the high-density QCD.The proceedings have been selected for coverage in: ? Index to Scientific & Technical Proceedings? (ISTP? / ISI Proceedings)? Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)? CC Proceedings ? Engineering & Physical Sciences
Download or read book Initial State Interactions and Single Spin Asymmetries in Drell Yan Processes written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We show that the initial-state interactions from gluon exchange between the incoming quark and the target spectator system lead to leading-twist single-spin asymmetries in the Drell-Yan process H[sub 1]H[sub 2][sup[up-arrow]][yields][ell][sup+][ell][sup -]X. The QCD initial-state interactions produce a T-odd spin-correlation[rvec S][sub H[sub 2]][center-dot][rvec P][sub H[sub 1]] x[rvec Q] between the target spin and the virtual photon production plane which is not power-law suppressed in the Drell-Yan scaling limit at large photon virtuality Q[sup 2] at fixed x[sub F]. The single-spin asymmetry which arises from the initial-state interactions is not related to the target or projectile transversity distribution[delta]q[sub H]. The origin of the single-spin asymmetry in[pi]p[up-arrow][ell][sup+][ell][sup -] is a phase difference between two amplitudes coupling the proton target with J[sub p][sup z]=[+-] 1/2 to the same final-state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. The calculation requires the overlap of target light-front wavefunctions with different orbital angular momentum:[Delta]L[sup z]= 1; thus the SSA in the Drell-Yan reaction provides a direct measure of orbital angular momentum in the QCD bound state. The single-spin asymmetry predicted for the Drell-Yan process[pi]p[up-arrow][yields][ell][sup+][ell][sup -]X is similar to the single-spin asymmetries in deep inelastic semi-inclusive leptoproduction[ell]p[up-arrow][yields][ell][prime][pi]X which arises from the final-state rescattering of the outgoing quark. The Bjorken-scaling single-spin asymmetries predicted for the Drell-Yan and leptoproduction processes high-light the importance of initial- and final-state interactions for QCD observables.
Download or read book Exclusive Reactions at High Momentum Transfer IV written by A. V. Radyushkin and published by World Scientific. This book was released on 2011 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Proceedings include talks given at the 4th Workshop on Exclusive Reactions at High Momentum Transfer at Jefferson Lab, Newport News, VA, USA, the world''s leading facility performing research on nuclear, hadronic and quark-gluon structure of matter. Exclusive reactions are becoming one of the major sources of information about the deep structure of the nucleons and other hadrons. The workshop focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground state and excited state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities. The topics include: generalized parton distributions, deeply virtual Compton scattering, deeply virtual meson production (DVMP), transverse structure of hadrons (TMD), hadron form factors - elastic and transition, quantum chromodynamics (perturbative, non-perturbative, lattice calculations), and physics to study at an Electron Ion Collider.
