Internal Spin Structure Of The Nucleon - Proceedings Of The Symposium

Internal Spin Structure Of The Nucleon - Proceedings Of The Symposium
Author: Vernon W Hughes
Publisher: World Scientific
Total Pages: 434
Release: 1995-07-14
Genre: Technology & Engineering
ISBN: 9814548804

The topic of the internal spin structure of the nucleon has become an unusually active subfield of particle and nuclear physics, together with the relevant technologies. This volume presents up-to-date coverage.All the talks given at the symposium can be found in the volume. In addition, selected articles are reprinted, including two early papers which record initial thinking about the topic, all experimental papers giving data on nucleon spin structure functions determined from polarized lepton-nucleon scattering, and two valuable previously unpublished papers.

The Spin Structure of the Proton

The Spin Structure of the Proton
Author: Steven D. Bass
Publisher: World Scientific
Total Pages: 212
Release: 2008
Genre: Science
ISBN: 9812709460

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 - 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. Book jacket.

Perspectives in the Structure of Hadronic Systems

Perspectives in the Structure of Hadronic Systems
Author: M.N. Harakeh
Publisher: Springer Science & Business Media
Total Pages: 361
Release: 2012-12-06
Genre: Science
ISBN: 1461525586

The last decade has been witness to many exciting and rapid developments in the fields of Nuclear Physics and Intermediate Energy Physics, the interface between Nuclear and Elementary Particle Physics. These developments involved to a large extent the sub nucleonic degrees of freedom in nuclei. In deep inelastic lepton scattering from nuclei, for example, it was observed that the quark structure of the nucleon is influenced by the nuclear medium. Also, the spin-dependent structure function of the nucleon was found to differ from sum rules based on SU(3) symmetry, a discrepancy referred to as the "spin crisis". In pion electroproduction at threshold and in the production of pions and other mesons in heavy ion collisions at intermediate energies interesting experimental results have been obtained, which triggered lively theoretical discussions. Furthermore, the search for the quark-gluon plasma phase of hadronic matter, a phase that is supposed to have existed in the first few seconds of the Big Bang, has been intensified. Not only were these developments accompanied by technical developments, such as the building of new experimental facilities, but also extensive theoretical efforts have been directed towards understanding these phenomena. These concerted efforts will hopefully lead to an understanding of the transition from the non-perturbative QCD regime to the perturbative one, in which the quark structure of nucleons is better understood. All of the aforementioned developments occur at a high pace, making it difficult to incorporate them into the courses offered to advanced students.

Electromagnetic Interactions and Hadronic Structure

Electromagnetic Interactions and Hadronic Structure
Author: Frank Close
Publisher: Cambridge University Press
Total Pages: 495
Release: 2009-07-23
Genre: Science
ISBN: 1139463810

Written by leading experts in the field, this book provides an authoritative overview on electromagnetic interactions. It describes the main features of the experimental data and the theoretical ideas used in their interpretation, and is an essential reference for graduate students and researchers in particle physics and electromagnetic interactions.

Spin 96 - Proceedings Of The 12th International Symposium On High-energy Spin Physics

Spin 96 - Proceedings Of The 12th International Symposium On High-energy Spin Physics
Author: J E J Oberski
Publisher: World Scientific
Total Pages: 906
Release: 1997-04-15
Genre:
ISBN: 9814546437

Experiments using highly polarized intense beams and targets, and theoretical studies of spin and polarization phenomena, are now providing us with numerous additional details of the electroweak and strong interactions and the structure of matter. The spin structure of the nucleon has been measured over wide ranges of kinematic variables, and the cross sections have been calculated to several orders in perturbative field theory. At present, the influence of the higher twist contributions, the gluon spin, and the quark orbital angular momentum are under scrutiny. Quantum chromodynamics (QCD) captures a lot of our experimental knowledge of hard polarized scattering processes. Can our understanding of such processes within QCD be further improved?Hyperons produced in high energy reactions show how puzzling strong interactions between hadrons still are. Spin observables in experiments at intermediate energy are used to test parity and charge symmetries. Will they also reveal, at low energy, a violation of time reversal symmetry? We are on the verge of using parity violation measurements at intermediate electron scattering energies to determine the amount of strange quark contributions to the neutral weak form factor of the nucleon. The polarization of the sea quarks is expected to be measured soon in W± decays produced in high energy polarized proton interactions. Will the jets in polarized Z⁰ decays show a definite handedness? These and many other topics are discussed in these proceedings.

Spin Structure of the Nucleon

Spin Structure of the Nucleon
Author: Erhard Steffens
Publisher: Springer Science & Business Media
Total Pages: 273
Release: 2012-12-06
Genre: Science
ISBN: 9401001650

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.

Proceedings of the First Workshop on Quark-Hadron Duality and Transition to PQCD

Proceedings of the First Workshop on Quark-Hadron Duality and Transition to PQCD
Author: Alessandra Fantoni
Publisher: World Scientific
Total Pages: 298
Release: 2006
Genre: Science
ISBN: 9812566848

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. Contents: Introduction and Review: Experimental and Theoretical Status: Duality in the Polarized Structure Functions (H 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 Thomas); Spin-Flavor Decomposition and Duality in Polarized SIDIS (X Jiang); Hadron Structure on the Back of an Envelope (A Thomas); Duality in Photoproduction: Duality in Vector Meson Production (A Donnachie); Onsef 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: Local Duality and Charge Symmetry Violation (F Steffens); Duality and QCD: Higher Twist Effects in Polarized DIS (D Stamenov); Quark-Hadron Duality and High Excitations (M Shifman); Highly Excited Hadrons in QCD and Beyond (M Shifman); Future Perspectives: Transverse Polarization and Quark-Hadron Duality (O Teryaev); Research Perspectives with the Jefferson Lab (K de Jager); Perspectives with PANDA (P Gianotti); Summary Talk (P Hoyer); Transverse Polarization and Quark Gluon Duality (O Teryaev); and other papers. Readership: Researchers, academics and lecturers in high energy, particle and nuclear physics.

Hadron Structure in Electroweak Precision Measurements

Hadron Structure in Electroweak Precision Measurements
Author: Nathan L. Hall
Publisher: Springer
Total Pages: 127
Release: 2015-07-24
Genre: Science
ISBN: 3319202219

This thesis examines the γZ box contribution to the weak charge of the proton. Here, by combining recent parity-violating electron-deuteron scattering data with our current understanding of parton distribution functions, the author shows that one can limit this model dependence. The resulting construction is a robust model of the γγ and γZ structure functions that can also be used to study a variety of low-energy phenomena. Two such cases are discussed in this work, namely, the nucleon’s electromagnetic polarizabilities and quark-hadron duality. By using phenomenological information to constrain the input structure functions, this important but previously poorly understood radiative correction is determined at the kinematics of the parity-violating experiment, QWEAK, to a degree of precision more than twice that of the previous best estimate. A detailed investigation into available parametrizations of the electromagnetic and interference cross-sections indicates that earlier analyses suffered from the inability to correctly quantify their model dependence.