Physics of spin-1 hadron is an unexplored topic in the high-energy region although spin-1/2 physics has been well investigated in the last decade. It is important to test our knowledge of hadron spin structure in a quite different field of spin physics. We discuss tensor structure functions, which do not exist for the spin-1/2 nucleon, in lepton scattering and in hadron reactions such as the po...

With relation to the RHIC spin programwe research the polarization effects in elastic proton-proton scattering at small momentum transfer and in the diffraction dip region. The calculations take into account the Coulomb-hadron interference effects including the additional Coulomb-hadron phase. In particular we show the impact of the form of the hadron potential at large distances on the behavio...

The impact of the form of the hadron potential at large distances on the behaviour of the hadron spin-flip amplitude at small angles is examined. The t-dependence of the spin-flip amplitude of high energy hadron elastic scattering is analyzed under different assumptions on the hadron interaction. It is shown that the long tail of the non-Gaussian form of the hadron potential of the hadron inter...

The role of gauge invariance in single-spin asymmetries. The Sivers single-spin asymmetry in photon-jet production. DESY-07-028 (2007), hep-ph/0703153. Single-transverse spin asymmetry in dijet correlations at hadron colliders. Gluonic pole cross-sections and single spin asymmetries in hadron-hadron scattering. JHEP 02, 029 (2007), hep-ph/0609206. The construction of gauge-links in arbitrary ha...

The impact of large-distance contributions on the behaviour of the slopes of the spin-non-flip and of the spin-flip amplitudes is analysed. It is shown that the long tail of the hadron potential in impact parameter space leads to a larger value of the slope for the spin-flip amplitude (without the kinematic factor √ |t|) than for the spin-non-flip amplitude. This effect is taken into account in...

It is shown that the euclidean origin of the instanton leads to the appearence of a large imaginary part in some diagrams for hadron production in quark-quark scattering. This phenomenon and instanton–induced quark spin-flip give the fundamental QCD mechanism for the observed large single-spin asymmetries in hadron-hadron and lepton-hadron interactions. 1 Talk presented at the Workshop ”Polariz...

By assuming that there is no significant intrinsic polarization of the gluon, we have computed the polarized quark contributions to the proton’s spin under SU(3) flavor symmetry breaking for the polarized sea and have performed a global leading-order QCD fit to obtain the spin-dependent quark distributions, which could be used as input for analyzing lepton-hadron and hadron-hadron collisions.