A general formalism, based on factorization theorem and pQCD hard interactions, is developed for the description of single spin effects in hadron-hadron inclusive processes. The transverse momentum, k⊥, of the quarks inside the hadrons and of the hadrons relatively to the fragmenting quark, is taken into account in distribution and fragmentation functions, and leads to possible non zero single ...

We investigate leading twist transverse momentum dependent origins of transverse spin asymmetries in hadron-hadron collisions. The chiral-odd T-odd distribution function with intrinsic transverse momentum dependence, which would signal an intrinsic handedness of quarks inside a hadron, could account for single spin asymmetries and at the same time for the large cos 2φ asymmetry in the unpolariz...

We investigate the inclusive production of prompt J/ψ mesons in polarized hadron-hadron, photon-hadron, and photon-photon collisions in the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD) providing all contributing partonic cross sections in analytic form. In the case of photoproduction, we also include the resolved-photon contributions. We present numerical results ap...

In order to extract information about behavior of polarized gluons in the nucleon, charmed hadron productions, i.e. D meson and Λ+c baryon productions, are studied in polarized pp reactions at BNL-RHIC energy. For these processes, the spin correlation asymmetry ALL between the target proton and the produced charmed hadron, and its statistical sensitivity δALL are calculated as functions of tran...

Within the QCD-improved parton model and assuming the factorization theorem to hold in the helicity basis and for higher twist contributions, we show how non zero single spin asymmetries in hadron-hadron high energy and moderately large pT inclusive processes can be obtained, even in massless perturbative QCD, provided the quark intrinsic motion is taken into account. A simple model is construc...

We discuss some experimental and theoretical results on single spin asymmetries (SSA) in high energy lepton-hadron and hadron-hadron reactions. In particular, recent results on meson SSA obtained by HERMES are considered in detail. We also discuss the SSA results obtained recently by COMPASS, as well as those from BRAHMS, PHENIX and STAR. Special attention is paid to a possible nonperturbative ...

The high energy hadron-hadron collisions produce various hyperons, in which large spin polarizations perpendicular to a production plane are observed at high Feynman-x (xF ) and low transverse momentum pT . For these collisions, we have proposed a global model on the basis of quark rearrangements concept. In order to produce a final state hyperon at high xF , we consider possible rearrangement ...

We study the strong coupling limit of the one-flavor and two-flavor massless 't Hooft models, large − N c-color QCD 2 , on a lattice. We use staggered fermions and the Hamiltonian approach to lattice gauge theories. We show that the one-flavor model is effectively described by the antiferro-magnetic Ising model, whose ground state is the vacuum of the gauge model in the infinite coupling limit;...

The amplitude of diffractive ρ (and open quark) leptoproduction on a polarized target is calculated in the leading log approximation of pQCD using the hadron-parton duality hypothesis. The spin-spin asymmetry is expressed in terms of the spin dependent gluon and quark structure functions in the small x region. Therefore the γ∗+p → ρ+ p reaction provides a promising tool to study the spin depend...