Related papers: Spin Physics through QCD Instantons
In this article we review the present understanding of azimuthal and single spin asymmetries for inclusive and semi-inclusive particle production in unpolarized and polarized hadronic collisions at high energy and moderately large…
These notes provide an introduction to polarization effects in deep inelastic processes in QCD. We emphasize recent work on transverse asymmetries, subdominant effects, and the role of polarization in fragmentation and in purely hadronic…
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 identify and calculate the instanton-induced contributions to deep inelastic scattering which correspond to nonperturbative exponential corrections to the coefficient functions in front of parton distributions of the leading twist.
A large body of evidence from lattice calculations indicates that instantons play a major role in the physics of light hadrons. This evidence is summarized, and recent results concerning the instanton content of the SU(3) vacuum, instanton…
A new mechanism for single spin asymmetries in strong interaction is proposed. It is based on instanton-induced nonperturbative chromomagnetic quark-gluon interaction. We estimate the contribution of this interaction to single spin…
Semi-inclusive hadron production in longitudinally polarized deep-inelastic lepton-nucleon scattering is a powerful tool for resolving the quark flavor decomposition of the proton's spin structure. We present the full…
We review the present status of our ongoing systematic study of the discovery potential of QCD-instanton induced events in deep-inelastic scattering at HERA.
Phenomena of rotation and oscillations of particle spin are discussed for particles rotating in storage ring. The fact that these effects are described by spin-dependent part of zero-angle scattering amplitude allows to use them for the…
The proton spin budget is discussed. Results are presented from inclusive and semi-inclusive deep inelastic scattering and from deeply virtual Compton scattering. They permit interpretations towards the determination of various…
We discuss the contributions of the transverse spin component of the target to the double-spin asymmetries in semi-inclusive deep inelastic scattering of longitudinally polarized electrons off longitudinally polarized protons.
We present a brief status report of our broad and systematic study of QCD-instantons at HERA.
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…
The main part of this talk is a review and summary of how QCD is used in two main areas of nuclear physics, namely in determining the quark flavor and spin content of the proton and in ultrarelativistic heavy ion collisions. Brief comments…
I present an introduction to the field of Quantum Chromodynamics (QCD) with emphasis on nucleon spin structure and perturbative methods. After a somewhat comprehensive overview of perturbative QCD, including the systematics of…
We compute the single-spin asymmetry $A_{UL}$ in semi-inclusive deep-inelastic scattering of unpolarized leptons and longitudinally polarized protons at large transverse momentum of the produced hadron. Our calculation is performed in…
We study the role of semi-classical QCD vacuum solutions in high energy scattering by considering the instanton contribution to hadronic cross sections. We propose a new type of instanton-induced interactions (``instanton ladder'') that…
Single-spin asymmetries in the semi-inclusive production of charged pions in deep-inelastic scattering from transversely and longitudinally polarized proton targets are combined to evaluate the subleading-twist contribution to the…
A natural consequence of the composite operator propagator-vertex description of deep inelastic scattering developed by the authors is that the anomalous suppression observed in the flavour singlet contribution to the first moment of the…
Lattice field theory provides a quantitative tool to study the role of nonperturbative semiclassical configurations in QCD. This talk briefly reviews our present understanding of the role of instantons in QCD and describes in detail new…