Related papers: Regge description of spin-spin asymmetry in photon…
We study spin asymmetries in diffractive $Q \bar Q$ and vector meson production which are sensitive to the spin-dependent part of the two-gluon-nucleon coupling. It is found that the $A_{ll}$ and $A_{lT}$ asymmetry in diffractive reactions…
The ``asymmetric'' matrix element <p-r|G...G|p> that appears in the pQCD description of hard diffractive electroproduction does not coincide with that defining the gluon distribution function f_g(x). I outline a pQCD formalism based on a…
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…
A detailed analysis is presented of the diffractive deep-inelastic scattering process $ep\to eXY$, where $Y$ is a proton or a low mass proton excitation carrying a fraction $1 - \xpom > 0.95$ of the incident proton longitudinal momentum and…
We obtain the gluon parton distribution functions (PDFs) in the proton within the extended light-front holographic QCD framework, where the proton couples with the spin-two Pomeron in Anti-de Sitter space, together with constraints imposed…
Diffractive hard scattering is interpreted as the effect of soft gluon exchanges between the emerging energetic quarks and the nucleon's color field, resulting in an overall color singlet exchange. Summing multiple gluon exchanges to all…
It is shown that the $A_{ll}$ asymmetry in diffractive $Q \bar Q$ leptoproduction is not small at HERA energies and dependent on the structure of the pomeron couplings and on the masses of produced quarks. The connection of this asymmetry…
The amplitude of diffractive $\rho$ (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…
We discuss diffractive dissociation of gluons into heavy quark pairs. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the…
We study in perturbative QCD the helicity ampltiudes of the process $\gamma^{*} p \to \rho p $ at large virtualities $Q$ of the photon $\gamma^{*}$. We estimate all spin flip amplitudes taking into account an important effect of the scale…
The proton diffractive structure function $F_2^{D(3)}$ measured in the H1 and ZEUS experiments at HERA is analyzed in terms of both Regge phenomenology and perturbative QCD evolution. A new method determines the values of the Regge…
We study $pp$ scattering at high energies and moderately large momentum transfer using a QCD--based model in which the proton is viewed as being composed of a quark and a diquark. This model leads to spin asymmetries which are neither small…
The measurement of the polarized gluon distribution function Delta G(x) from photon-gluon fusion processes in electron-proton deep inelastic scattering producing two jets has been investigated. The study is based on the MEPJET and PEPSI…
A new model for the exchange of two gluons between the virtual photon and the proton, in non-diffractive deeply inelastic electron-proton scattering, is developed and studied. This model relies on a perturbative calculation, previously…
The spin correlation parameters, polarization - $A_{N}$ and double spin correlation parameters - $A_{NN}$, are calculated in the framework of dynamical model (GKS) of the hadron-hadron interection in the whole region of small angles and for…
We propose a new formula for extracting the polarized gluon distribution from the large-$p_T$ light hadron pair production for semi-inclusive processes in polarized deep inelastic scattering. In general, a large-$p_T$ hadron pair is…
We present the first inclusive jet longitudinal double spin asymmetry A_LL and differential cross-section measurement from STAR. This analysis reflects ~1 pb^-1 of polarized pp data taken at sqrt{s}=200 GeV with beam polarizations of 30-45%…
We consider the dependencies of spin asymmetries in the diffractive $J/\Psi$ and $Q \bar Q$ leptoproduction at HERA energies on the structure of the pomeron-proton coupling. It is shown that it is difficult to study the spin structure of…
We report high-precision measurements of the longitudinal double-spin asymmetry, $A_{LL}$, for midrapidity inclusive jet and dijet production in polarized $pp$ collisions at a center-of-mass energy of $\sqrt{s}=200\,\mathrm{GeV}$. The new…
Plans are underway to measure spin asymmetries at large momentum transfer in hadron hadron collisions at RHIC and elsewhere. Proposals have focused on measuring quark transversity and quark and gluon helicity distributions in the nucleon.…