Download or read book Gdh 2002 Proceedings Of The Second International Symposium On The Gerasimov drell hearn Sum Rule And The Spin Structure Of The Nucleon written by Marco Anghinolfi and published by World Scientific. This book was released on 2003-06-13 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the GDH 2002 symposium. It is a review of the most recent results on the nucleon spin structure and related sum rules using real and virtual photons. The latest theoretical developments and the new high precision data from different laboratories are presented and discussed. The book provides a comprehensive picture of the nucleon spin studies from the perturbative domain down to the resonance and low momentum transfer region.

Download or read book GDH 2002 written by Marco Anghinolfi and published by World Scientific. This book was released on 2003 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing the proceedings of the GDH 2002 symposium, this is a review of results on the nucleon spin structure and related sum rules using real and virtual photons. Theoretical developments and high precision data from different laboratories are presented and discussed. The work offers a comprehensive picture of the nucleon spin studies from the perturbative domain down to the resonance and low momentum transfer region.

Download or read book GDH 2000 written by D. Drechsel and published by World Scientific. This book was released on 2001 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: The history of spin in general, and of the nucleon spin structure in particular, has been full of surprises. For the past 25 years deep inelastic lepton scattering has been studied to determine the carriers of the nucleon spin. However, it was realized only recently that a full understanding of the nucleon spin will also require detailed information on the helicity structure in the resonance region, i.e. in the realm of nonperturbative QCD.This volume gives a status report on the spin structure in the nucleon resonance region, focusing on: new experimental results from SLAC and HERMES; a first glance at the JLab experiments to map out the spin structure functions at low and intermediate four-momentum transfers; the pioneering experiment at MAMI (Mainz) to determine the Gerasimov-Drell-Hearn sum rule for real photons; and recent theoretical concepts and investigations to describe the spin structure in the frameworks of higher twist expansion, phenomenological models and chiral perturbation theory.

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 GDH 2002 written by Marco Anghinolfi and published by World Scientific. This book was released on 2003 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the GDH 2002 symposium. It is a review of the most recent results on the nucleon spin structure and related sum rules using real and virtual photons. The latest theoretical developments and the new high precision data from different laboratories are presented and discussed. The book provides a comprehensive picture of the nucleon spin studies from the perturbative domain down to the resonance and low momentum transfer region.

Download or read book Gdh 2000 The Gerasimov drell hearn Sum Rule The Nucleon Spin Structure In The Resonance Region written by Dieter Drechsel and published by World Scientific. This book was released on 2001-02-05 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: The history of spin in general, and of the nucleon spin structure in particular, has been full of surprises. For the past 25 years deep inelastic lepton scattering has been studied to determine the carriers of the nucleon spin. However, it was realized only recently that a full understanding of the nucleon spin will also require detailed information on the helicity structure in the resonance region, i.e. in the realm of nonperturbative QCD.This volume gives a status report on the spin structure in the nucleon resonance region, focusing on: new experimental results from SLAC and HERMES; a first glance at the JLab experiments to map out the spin structure functions at low and intermediate four-momentum transfers; the pioneering experiment at MAMI (Mainz) to determine the Gerasimov-Drell-Hearn sum rule for real photons; and recent theoretical concepts and investigations to describe the spin structure in the frameworks of higher twist expansion, phenomenological models and chiral perturbation theory.

Download or read book Nstar 2004 Proceedings Of The Workshop On The Physics Of Excited Nucleons written by Viatcheslav Kouznetsov and published by World Scientific. This book was released on 2004-11-23 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers recent advances in the field of nucleon resonances presented at the IX International Workshop on the Physics of Excited Baryons, NSTAR2004. A complete overview of the most recent experimental results obtained worldwide on baryon spectroscopy is presented together with theoretical progress on related topics ranging from resonance parameters extraction to lattice-QCD calculations through effective field theory. Of particular interest, a large part of the book is devoted to exotic states with quantum numbers of pentaquarks, whose recent discovery represents a new chapter in hadronic physics.The proceedings have been selected for coverage in:• Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)• CC Proceedings — Engineering & Physical Sciences

Download or read book Electromagnetic Interactions In Nuclear And Hadron Physics Proceedings Of The International Symposium written by Mamoru Fujiwara and published by World Scientific. This book was released on 2002-06-27 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the following topics: (1) meson and hadron production by real and virtual photon interaction with nucleons and nuclei; (2) astrophysical studies via photoreactions and hadron reactions; (3) new technologies for the electromagnetic probes and detector development; (4) nuclear structure studies with electromagnetic probes; (5) fundamental symmetries with electromagnetic probes and related problems.The proceedings have been selected for coverage in:• Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)

Download or read book Acta Physica Polonica written by and published by . This book was released on 2006 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the International Symposium on Meson Nucleon Physics and the Structure of the Nucleon written by and published by . This book was released on 2002 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Generalised GDH Sum Rule written by Vincent Sulkosky and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Gerasimov-Drell-Hearn (GDH) sum rule was originally derived for real photon absorption (corresponding to Q{sup 2}=0) and has been generalized to finite Q{sup 2}. The goals of Jefferson Lab experiment E97-110 are to perform a precise measurement of the generalized GDH integral and the moments of the neutron spin structure functions in order to study their Q{sup 2} dependence between 0.02 and 0.3 (GeV/c){sup 2}. This Q{sup 2} range will allow us to extrapolate to the real photon point for {sup 3}He and the neutron. Furthermore the low Q{sup 2} predictions of Chiral Perturbation Theory and its limits of applicability can be tested. The measurements will provide new constraints on understanding the {sup 3}He and neutron spin structure and contribute to the understanding of the nucleon resonances. The acquisition of data was completed in August of 2003 using the Jefferson Lab high polarization continuous-wave electron beam, the Hall A polarized {sup 3}He target, and the new Hall A septum magnet, which allows measurements at forward angles of 6 and 9 degrees. The status and prospects of the data analysis will be discussed.

Download or read book Excited Nucleons And Hadron Structure Proceedings Of The Nstar 2000 Conference written by Volker Burkert and published by World Scientific. This book was released on 2001-02-28 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: The conference NSTAR 2000 was part of a series of conferences and workshops that began in New York in 1988. Since then, the field of excited nucleons and hadron structure has developed enormously, and the scope has broadened. Most significantly, new experimental facilities have come into operation, allowing precise measurements of resonance couplings and transition form factors. The search for “missing” quark model states and gluonic excitations in complex hadronic channels is now possible.On the theory side, new and promising developments have emerged: quark models with meson degrees of freedom, hybrid baryon models, and studies of baryons in the limit of many colors. For the first time, lattice QCD has been employed to calculate masses of excited nucleons. Nucleon resonances are now recognized as providing significant contributions to the nucleon spin sum rules, as well as the Gerasimov-Drell-Hearn and Bjorken integrals, at finite momentum transfer.

Download or read book Spin Structure Of The Nucleon Proceedings Of The The Riken Symposium written by Toshi-aki Shibata and published by World Scientific. This book was released on 1996-08-30 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: After about three decades of experimental and theoretical efforts, the structure of the nucleon (proton and neutron) is now fairly well understood based on quantum chromodynamics, but only if averaged over its spin. As the recent “proton spin crisis” revealed, we do not understand much about the nucleon structure when its spin is polarized to a specific orientation. We expect that our understanding on this challenging problem will soon be significantly improved by the RHIC-Spin and other experiments in the near future, as well as by the lattice- and perturbative-QCD theoretical calculations. The purpose of this symposium was to summarize the current understanding and discuss the future perspective of this problem with experimental and theoretical physicists from both high-energy and nuclear physics communities.The symposium covered the overview of the structure studies, updates on the experimental results from CERN, SLAC, DESY, FNAL, and KEK, future experiments at RHIC, and recent theoretical developments (18 presentations, 113 participants).

Download or read book The Generalized GDH Sum Rule and the Spin Structure of the Neutron written by Jin Yuan and published by . This book was released on 2008 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nucleon spin structure has been of great interest since the CERN SMC experiment found that quarks carry only a small fraction of the nucleon spin. Since naively quarks are expected to carry most of the nucleon's spin, this observation became known as spin crisis. The availability of polarized beams and targets since the late 1970's has allowed the measurement of the nucleon spin structure functions, and furthermore checks of Quantum Chromodynamics (QCD), the theory of strong interactions, in its perturbative regime. Sum rules involving the spin structure of the nucleon offer an important opportunity to study QCD. It has recently been shown that the GDH sum rule and Bjorken sum rule are both special examples of a more general sum rule that applies to polarized electron scattering off nucleons. This generalized sum rule applies at all Q2. By studying the Q2 evolution of the extended GDH sum, one learns about the transition from quark-like behavior at high Q2, larger than 1 GeV2, to hadronic-like behavior at low Q2, close to 0. The transition between these two regimes is far from understood; it is a key issue in our understanding of the strong interaction. During mid 2003, we measured inclusive polarized cross sections in the scattering of high energy polarized electrons off the Jefferson Lab Hall A polarized 3He target. A strained GaAs photocathode was utilized in the polarized electron gun to provide an electron beam with a polarization of 70%. The high density polarized 3He target, based on optical pumping of rubidium and spin echange, was used as an effective neutron target. The polarization of the target was maintained at about 40% at beam currents as high as 15 muA. The target polarization was measured by Nuclear Magnetic Resonance methods calibrated using two independent techniques: proton thermal polarization (water calibration) and Electron Paramagnetic Resonance (EPR). The relative uncertainty on the target polarization was better than 4%. The target was operated with both longitudinal and transverse target spin orientations. In Jlab Hall A, in order to reach very low Q2 in experiment E97-110, a new septum magnet was used to make very small scattering angle measurements with the Hall A right spectrometer. The left spectrometer was used without a septum to monitor an unpolarized carbon target, downstream of the polarized 3He target, to check for possible false asymmetries. A wide range of data were measured: beam energies from 1.15 to 4.40 GeV were used at scattering angles of 6 and 9 degrees. The invariant mass W ranged across the resonance region, from inelastic threhold to the beginning of the deep inleastic region (W = 2 GeV). From the measured spin-dependent cross sections we extract the 3He spin structure functions g_{1} and g_{2}. Finally, we determined the extended GDH sum and other quantities for the Q2 range between 0.04 and 0.3 GeV2. The range of data allows extrapolation to the real photon point, studying the convergence of the sum rule, determining the slope of GDH sum rule as Q2 to 0 to check Chiral Perturbation Theory, and overlap with the previous higher Q2 experiment E94-010.

Download or read book Study of Spin Sum Rules and the Strong Coupling Constant at Large Distances written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent results from Jefferson Lab on sum rules related to the spin structure of the nucleon. We then discuss how the Bjorken sum rule with its connection to the Gerasimov-Drell-Hearn sum, allows us to conveniently define an effective coupling for the strong force at all distances.

Download or read book CERN Courier written by European Organization for Nuclear Research and published by . This book was released on 1959 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: This journal is devoted to the latest research on physics, publishing articles on everything from elementary particle behavior to black holes and the history of the universe.

Download or read book Sum Rule Measurements of the Spin dependent Compton Amplitude nucleon Spin Structure at Q2 written by and published by . This book was released on 1995 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy weighted integrals of the difference in helicity-dependent photo-production cross sections (?{sub {1/2}} -?32) provide information on the nucleons̀ Spin-dependent Polarizability , and on the spin-dependent part of the asymptotic forward Compton amplitude through the Drell-Hearn-Gerasimov (DHG) sum rule. (The latter forms the Q2=0 limit of recent spin-asymmetry experiments in deep-inelastic lepton-scattering.) There are no direct measurements of?{sub {1/2}} or?32, for either the proton or the neutron. Estimates from current?-photo-production multipole analyses, particularly for the proton-neutron difference, are in good agreement with relativistic-l-loop Chiral calculations (?PT) for? but predict large deviations from the DHG sum rule. Either (a) both the 2-loop corrections to the Spin-Polarizability are large and the existing multipoles are wrong, or (b) modifications to the Drell-Hearn-Gerasimov sum rule are required to fully describe the isospin structure of the nucleon. The helicity-dependent photo-reaction amplitudes, for both the proton and the neutron, will be measured at LEGS from pion-threshold to 470 MeV. In these double-polarization experiments, circularly polarized photons from LEGS will be used with SPHICE, a new frozen-spin target consisting of {rvec H} · {rvec D} in the solid phase. Reaction channels will be identified in SASY, a large detector array covering about 80% of 4?. A high degree of symmetry in both target and detector will be used to minimize systematic uncertainties.