Related papers: The Spin Structure of the Proton
The study of two spin asymmetries in hadron-hadron collisions probes the details of fundamental particle interactions in ways infeasible to machines with unpolarized collisions. Within reach is how the proton spin is distributed among its…
A qualitative QCD analysis and a quantitative model calculation are given to show that the constituent quark model remains a good approximation even with the nucleon spin structure revealed in polarized deep inelastic scattering taking into…
Transverse single spin asymmetries can be a challenging tool in our understanding of the internal structure of hadrons. Some aspects and recent results are discussed.
We discuss our present understanding of the transverse spin structure of the nucleon and of related properties originating from parton transverse motion. Starting from the transversity distribution and the ways to access it, we then address…
Structure functions of the spin-1 deuteron will be investigated experimentally from the late 2020's at various facilities such as Thomas Jefferson National Accelerator Facility, Fermi National Accelerator Laboratory, nuclotron-based ion…
QCD suggests that gluons in the nucleon play an important role in {\it so-called} ``the proton spin problem''. In this talk, the behavior of the polarized gluon distribution in the nucleon is discussed by using the positivity condition of…
The structure function of the proton has been investigated and has been found to possess the power law behaviour in conformity with the empirical fits to the experimental findings. We have estimated F$_{2}$(x, Q$^{2}$)/F$_{2}$(x,…
We are on the way to obtaining multi-dimensional "pictures" of the proton. The field is bursting with activities, both from the theoretical and experimental side. A brief selection of important achievements of the last years and open…
The proton spin puzzle denotes the challenge of describing the proton's spin in terms of the angular momenta of the quarks and gluons which comprise it. These quarks and gluons carry a fraction $x$ of the proton's momentum. Contributions…
The spin structure of the pion is discussed by transforming the wave function for the pion in the naive quark model into a light-cone representation. It is shown that there are higher helicity ($\lambda_{1}+\lambda_{2}=\pm1$) states in the…
The chiral quark model with a broken U(3) symmetry gives a simple and unified account for the proton spin and flavor puzzles, as well as the octet baryon magnetic moments.
Developments in lattice field theory and computer technology have led to dramatic advances in the use of lattice QCD to explore the quark structure of hadrons. This talk will describe selected examples, including structure functions,…
We provide an introduction to the ideas of spin-dependent deep-inelastic scattering. Recent experimental results are summarised and possible explanations related to the axial anomaly presented. Further experiments that could greatly clarify…
In this paper we review the basics of magneto-rotational properties of neutron stars focusing on spin-up/spin-down behavior at different evolutionary stages. The main goal is to provide equations for the spin frequency changes in various…
Parallel to the construction of gauge invariant spin and orbital angular momentum for QED in paper (I) of this series, we present here an analogous but non-trivial solution for QCD. Explicitly gauge invariant spin and orbital angular…
The physics of the gravitational form factors of the proton, and their understanding within quantum chromodynamics, has advanced significantly in the past two decades through both theory and experiment. This Colloquium provides an overview…
The status of the proton radius puzzle (as of the date of the Confer- ence) is reviewed. The most likely potential theoretical and experimental explanations are discussed. Either the electronic hydrogen experiments were not sufficiently…
It is shown that the quark-parton model in the standard infinite momentum approach overestimate the proton spin structure function $g_1(x)$ in comparison with the approach taking consistently into account the internal motion of quarks…
We present results on the spin carried by quarks and gluons in the nucleon using lattice QCD simulations with physical values of the light, strange and charm quark masses. We also discuss selective results on the x-dependence of parton…
We present the first calculation of the transverse spin structure of the pion in lattice QCD. Our simulations are based on two flavors of non-perturbatively improved Wilson fermions, with pion masses as low as 400 MeV in volumes up to (2.1…