SU (2) L × SU (2) R and U (1) A restorations high in the hadron spectrum and what it tells us about. Abstract Recent data for highly excited mesons suggest that not only the chiral SU (2) L × SU (2) R symmetry of QCD is restored high in the spectrum but also the U (1) A symmetry. This means that it is not a confining interaction in QCD which triggers the spontaneous breaking of chiral symmetry....

I study the effect of scalar and spin-orbit absorption potentials, in the production of a nonzero Sivers-like asymmetry in hadron-hadron high energy collisions (DrellYan and single spin asymmetries). A basic model is built for the intrinsic state of a quark in the projectile hadron. S-wave and P-wave 2-component states are considered. Before the hard event, this quark is subject to absorbing me...

High energy multiparticle photoproduction off nuclear targets is studied. The photon is assumed to interact in direct scattering processes or as a resolved qq̄-state according to the Generalized Vector Dominance Model. In the description of resolved interactions multiple soft and hard processes in each qq̄-nucleon interaction are taken into consideration. The model, formulated within the framewor...

Abstract. We discuss the production of charmonium states in antiproton-nucleus collisions at the ψ ′ threshold. It is explained that measurements in p̄A collisions will allow to get new information about the strengths of the inelastic J/ψN and ψ N interaction, on the production of Λc and D̄ in charmonium-nucleon interactions and for the first time about the nondiagonal transitions ψ N → J/ψN. The...

The interaction region of hard exclusive hadron scattering can have a large transverse size due to endpoint contributions, where one parton carries most of the hadron momentum. The endpoint region is enhanced and can dominate in processes involving multiple scattering and quark helicity flip. The endpoint Fock states have perturbatively short lifetimes, hence are not Sudakov suppressed and scat...

In this paper we fix our attention, on hadron structure, and show that also the strong interaction strength αS, ordinarily called the “(perturbative) coupling–constant square”, can be evaluated within our theory, and found to decrease (increase) as the “distance” r decreases (increases). This yields both the confinement of the hadron constituents, and their asymptotic freedom: in qualitative ag...