Related papers: Proton spin structure and the axial U(1) problem
This article reviews our present understanding of the QCD spin structure of the proton. We first outline the proton spin puzzle and its possible resolution in QCD. We then review the present and next generation of experiments to resolve the…
This article reviews our present understanding of QCD spin physics: the proton spin puzzle and new developments aimed at understanding the transverse structure of the nucleon. We discuss present experimental investigations of the nucleon's…
The twenty years since the announcement of the proton spin crisis by the European Muon Collaboration has seen tremendous progress in our knowledge of the distribution of spin within the proton. The problem is reviewed, beginning with the…
A number of lines of investigation into the structure of the nucleon have converged to the point where we believe that one has a consistent explanation of the well known proton spin crisis.
Our knowledge on the nucleon spin structure has greatly improved over the last twenty years or so, but still many fundamental questions remain unsolved. I will try to review some of the puzzling aspects of the origin of the nucleon spin. I…
The object of this brief review is to reconcile different points of view on how the spin of proton is made up from its constituents. On the basis of naive quark model with flavour symmetry such as isospin or SU(3) one finds a static…
Understanding the spin structure of the proton is one of the main challenges in hadronic physics. While the concepts of spin and orbital angular momentum are pretty clear in the context of non-relativistic quantum mechanics, the…
Our knowledge of the nucleon spin structure has greatly improved over the last twenty years or so, but still many fundamental questions remain unsolved. I will try to review some of the puzzling aspects of the structure of the nucleon spin,…
The proton spin puzzle has challenged our understanding of QCD for the last 20 years. We survey new developments in theory and experiment. The proton spin puzzle seems to be telling us about the interplay of valence quarks with chiral…
We present an overview of recent experimental and theoretical advances in our understanding of the spin structure of protons and neutrons.
We define a constituent quark within QCD. It is shown that the spin of such a quark and hence also the spin of the nucleon reduced due to $\bar{q}q$-pairs, in agreement with experiment. A solution to the spin problem is given.
A brief summary of the theoretical and experimental knowledge of the spin structure of the proton is presented. The helicity distributions of quark and gluons are discussed, together with their related sum rules. The transversity…
Since the announcement of the proton spin crisis by the European Muon Collaboration there has been considerable progress in unravelling the distribution of spin and orbital angular momentum within the proton. We review the current status of…
The relatively small fraction of the spin of the proton carried by its quarks presents a major challenge to our understanding of the strong interaction. Traditional efforts to explore this problem have involved new and imaginative…
We investigate the relation between the topology of a nucleon and its spin composition. We approach this question in (1+1) dimensional single-flavor QCD with a large number of color. In this limit the theory can be shown to be dual to the…
We summarise the present status of the proton spin problem and the physics possibilities for future polarized ep and pp colliders. This summary is based on the presentations and discussion sessions at the workshop ``The Spin Structure of…
The present status of the nucleon's spin structure is reviewed with emphasis on new experimental results.
The proton is a composite object with spin one-half, understood to contain highly relativistic spin one-half quarks exchanging spin-one gluons, each possibly with significant orbital angular momenta. While their fundamental interactions are…
We review the theory and present status of the proton spin problem with emphasis on the transition between current quarks and constituent quarks in QCD.
We discuss the tremendous progress that has been towards an understanding of how the spin of the proton is distributed on its quark and gluon constituents. This is a problem that began in earnest twenty years ago with the discovery of the…