The Spin Structure Of The Proton

The Spin Structure Of The Proton
Author: Steven D Bass
Publisher: World Scientific
Total Pages: 212
Release: 2007-11-06
Genre: Science
ISBN: 981447455X

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.

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.

Beam Line

Beam Line
Author:
Publisher:
Total Pages: 338
Release: 1997
Genre: Particle beams
ISBN:

Testing Qcd Through Spin Observables In Nuclear Targets

Testing Qcd Through Spin Observables In Nuclear Targets
Author: Jian-ping Chen
Publisher: World Scientific
Total Pages: 338
Release: 2003-01-16
Genre: Science
ISBN: 9814486663

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?

60 Years Of Cern Experiments And Discoveries

60 Years Of Cern Experiments And Discoveries
Author: Herwig Schopper
Publisher: World Scientific
Total Pages: 452
Release: 2015-07-13
Genre: Science
ISBN: 9814644161

The book is a compilation of the most important experimental results achieved during the past 60 years at CERN - from the mid-1950s to the latest discovery of the Higgs particle. Covering the results from the early accelerators at CERN to those most recent at the LHC, the contents provide an excellent review of the achievements of this outstanding laboratory. Not only presented is the impressive scientific progress achieved during the past six decades, but also demonstrated is the special way in which successful international collaboration exists at CERN.