Download or read book Nucleon Spin Structure Functions from HERMES The First Year written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: HERMES, [und HE]RA[und Me]asurement of[und S]pin, is a second generation exper to study the spin structure of the nucleon by using polarized internal gas targets in the HERA 28 GeV electron storage ring. Scattered positrons and coincident hadrons are detected in an open geometry spectrometer which includes particle identification. Inclusive data with polarized[sup 3]He give the spin structure function[ital g[sup n][sub 1](x)] and the Ellis-Jaffe integral RR[Lambda]=[integral][sub 0][sup 1][ital g[sup n][sub 1](x)dx] for the neutron. The semi-inclusive spin asymmetries are a unique and sensitive probe of the flavor dependence of quark helicity distributions and properties of the quark sea. Data taken in 1995 with unpolarized hydrogen and deuterium targets provide measurements of the flavor distributions of sea and valence quarks. In a preliminary analysis, [Lambda][sup[ital n]][sub 1]= -0.032[+-]0. 013[sub[ital stat.]][+-] O.017[sub[ital syst.]] is obtained at Q[sup 2]= 3(GeV/c)[sup 2] for the Ellis-Jaffe integral.
Download or read book Spin Structure of the Nucleon written by Erhard Steffens and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive survey of the most recent results from the field of quark-gluon structure of the nucleon, in particular how the spin of the nucleon is shared by its constituents. After very intriguing results from CERN and SLAC at the end of the 1980s, the last decade has seen a set of second-generation experiments at high energy accelerators that have yielded precise information on the solution of the 'Spin Crisis' - as well as opening up new questions. The articles are written by experts from the leading collaboration and theory groups as well as providing an expert summary of the state of the art, the book points the way to future research directions. Its main focus is on semi-inclusive and exclusive measurements of deep inelastic lepton scattering, which enables for the first time the determination of the flavor-separated quark spin distributions. Future developments on generalized parton distributions and their interpretation as well as the transverse spin structure are also covered. An indispensable volume for all working in hadronic physics.
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 The Spin Structure Of The Nucleon written by Bernard Frois and published by World Scientific. This book was released on 1998-02-24 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: From its early beginnings at SLAC in the 1970's, the study of nucleon spin structure using polarized lepton beams and polarized nucleon targets has become increasingly important in nuclear and particle physics, with current experiments at several of the world's high energy and nuclear physics laboratories (CERN, DESY, SLAC and Jefferson Lab) and with enormous related theoretical studies. The understanding of the fascinating but complicated problem of nucleon spin structure has progressed substantially, but fundamental questions remain and it can be confidently predicted that future activity will be high.The Erice Course on The Spin Structure of the Nucleon covered both the experimental and theoretical aspects of the subject, and this volume includes the lectures given at the School. In many cases the lecture material has been extended and updated by the authors. In addition, several recent publications on experimental work have been added in an appendix.
Download or read book The Spin Structure of the Proton written by Steven D. Bass and published by World Scientific. This book was released on 2008 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the main challenges in nuclear and particle physics in the last 20 years has been to understand how the proton''s spin is built up from its quark and gluon constituents. Quark models generally predict that about 60% of the proton''s spin should be carried by the spin of the quarks inside, whereas high energy scattering experiments have shown that the quark spin contribution is small OCo only about 30%. This result has been the underlying motivation for about 1000 theoretical papers and a global program of dedicated spin experiments at BNL, CERN, DESY and Jefferson Laboratory to map the individual quark and gluon angular momentum contributions to the proton''s spin, which are now yielding exciting results. This book gives an overview of the present status of the field: what is new in the data and what can be expected in the next few years. The emphasis is on the main physical ideas and the interpretation of spin data. The interface between QCD spin physics and the famous axial U(1) problem of QCD (eta and etaprime meson physics) is also highlighted. Sample Chapter(s). Chapter 1: Introduction (159 KB). Contents: Spin Experiments and Data; Dispersion Relations and Spin Sum Rules; g 1 Spin Sum Rules; Fixed Poles; The Axial Anomaly, Gluon topology and g (0) A; Chiral Symmetry and Axial U(1) Dynamics; QCD Inspired Models of the Proton Spin Problem; The Spin-Flavour Structure of the Proton; QCD Fits to g 1 Data; Polarized Quark Distributions; Polarized Glue o g(x, Q 2 ); Transversity; Deeply Virtual Compton Scattering and Exclusive Processes; Polarized Photon Structure Functions; Conclusions and Open Questions: How Does the Proton Spin?. Readership: Academics, as well as physicists working on particle and nuclear physics at the interface of theory and experiment.
Download or read book Proposal to Measure Spin structure Functions and Semi exclusive Asymmetries for the Proton and Neutron at HERA written by and published by . This book was released on 1995 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nucleon spin physics will be studied in the HERMES experiment, that will use polarized internal targets of essentially pure atomic H, D, and 3He in the HERA electron storage ring at DESY. A series of measurements of spin-dependent properties of the nucleon and few-body nuclei will be made; the spin structure function g1(x) of the proton and neutron will be measured to test the Bjorken sum rule and study the fraction of the nucleon spin carried by quarks; the spin structure function g2W, sensitive to quark-gluon correlations, and the structure functions b1(x), and [Delta](x), sensitive to nuclear binding effects, will be measured; and, using the particle identification capability of the HERMES detector, pions will be detected in coincidence with the scattered electrons. The coincident hadron measurements represent the most important extension that can be made at this time to the existing measurements on the nucleon spin structure functions because they provide information about the flavor-dependence of the quark spin distribution in the nucleon. Argonne is providing the Cerenkov counter to be used for particle identification and developing the drifilm coating technique for the ultrathin target cell required for this experiment. The HERMES collaboration intends to use polarized targets with the highest available figures of merit, and the Argonne laser-driven source offers the most promise for a significant advance in present-day targets.
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 Precision Measurements of the Spin dependent Structure Functions Gp1 and Gd1 of the Proton and the Deuteron and Extraction of the Neutron Spin Structure Function Gn1 at HERMES written by Friedrich-Alexander-Universität Erlangen-Nürnberg. Naturwissenschaftliche Fakultät and published by . This book was released on 2005 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book XX International Symposium on Lepton and Photon Interactions at High Energies written by Juliet Lee-Franzini and published by World Scientific. This book was released on 2002 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt: This important book covers topics that are of major interest to the high energy physics community, including the most recent results from flavour factories, dark matter and neutrino physics. In addition, it considers future high energy machines.
Download or read book Physics Division Annual Report written by Argonne National Laboratory. Physics Division and published by . This book was released on 1995 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particles And Nuclei Panic 96 Proceedings Of The 14th International Conference written by Carl Carlson and published by World Scientific. This book was released on 1997-02-21 with total page 787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to phenomena that are of interest to both particle and nuclear physicists. The topics include nucleon structure (including spin structure), electron, neutrino, and hadron scattering from nucleons and nuclei, strange matter, the standard model, theory of nucleons and nuclei from both the QCD and nucleon-meson viewpoints, new experimental techniques, and new facilities.
Download or read book The Heart of the Matter from Nuclear Interactions to Quark Gluon Dymanics sic written by J.-F. Mathiot and published by Atlantica Séguier Frontières. This book was released on 1995 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transversity 2005 written by Dr. Vincenzo Barone and published by World Scientific. This book was released on 2006 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: The notion of transversity in hadronic physics has been with us for over 25 years. Intriguing though it might have been, for much of that time transversity remained an intangible and remote object, of interest principally to a few theoreticians. In recent years transversity and transverse-spin effects in general have grown as both theoretical and experimental areas of active research. This increasing attention has now matured into a thriving field with a driving force of its own. The ever-growing bulk of data on asymmetries in collisions involving transversely polarised hadrons demands a more solid and coherent theoretical basis for its description. Indeed, it now appears rather clear that transversity and other closely related properties play a significant role in such phenomena.As part of a Ministry-funded inter-university Research Project, this workshop was organised to gather together experimentalists and theoreticians engaged in investigating the nature of transverse spin in hadronic physics, with the intent of favouring the exchange of up-to-date theoretical and experimental ideas and news on the subject. Over 70 physicists took part and very nearly all the major experiments involved in transverse-spin studies were officially represented, as too were the main theory groups working in the field. New results and new analyses sparked many interesting and lively discussions.
Download or read book Energy and Water Development Appropriations for 1996 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 1995 with total page 2698 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deep Inelastic Scattering Proceedings Of The 8th International Workshop written by John A Gracey and published by World Scientific. This book was released on 2001-02-22 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume focusses on four main topics: structure functions, tests of quantum chromodynamics, physics at the highest Q2 and p2T, and high energy scattering and diffraction. Comprehensive review articles on hadronic and photon structure, lepton-parton and parton-parton physics as well as future experimental opportunities are presented, together with a special lecture on HERA's legacy after the first decade of operation.
Download or read book Deep Inelastic Scattering And Related Phenomena written by Giulio D'agostini and published by World Scientific. This book was released on 1997-03-15 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt: This workshop is the fourth of a series initiated in Durham (March 93), followed by Eilat (February 94) and Paris (April 95). The large interest and the great inflow of experimental data, coming mainly from HERA, are some of the reasons behind the decision to have this annual meeting, presently the most important one for this area of research. During the workshop, experimental results and theoretical aspects have been reported on subjects, which have been organised by working groups on: 1) hadron structure functions; 2) photoproduction and photon structure; 3) diffractive interactions; 4) hadronic final states; 5) spin effects in lepton nucleon scattering; 6) special session on theoretical advances. While the contributions to the working groups offer hot material for specialists, the reports by the conveners, as well as other contributions to the plenary sessions, offer to nonspecialists a complete overview of this research field.
Download or read book Baryons 2002 written by Carl Carlson and published by World Scientific. This book was released on 2003 with total page 705 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the latest developments in the area of three-quark systems. Emphasis is given to the discussion of new experimental results in the areas of form factors, unpolarized and polarized structure functions, and baryon structure and spectroscopy. Of particular interest are the new theoretical developments in the area of generalized parton distributions and lattice quantum chromodynamics.
