Related papers: Unintegrated gluon distribution from forward polar…
The gluon content of the proton, in the high-energy regime, is embodied by the unintegrated gluon distribution (UGD), which describes the gluon emission probability, with a given longitudinal momentum fraction and transverse momentum. The…
The gluon content of the proton is embodied by the unintegrated gluon distribution (UGD), which has universal validity. In literature many models of UGD have been proposed so far. The polarized $\rho$-meson leptoproduction at HERA offers a…
We consider the possibility of a direct determination of the polarized gluon density in the proton using charm production with polarized beams at HERA. We study total cross sections and distributions at leading order using different…
We calculate cross sections for the exclusive diffractive leptoproduction of $\rho$-mesons, $\gamma^*~p~\to~\rho~p$, within the framework of high-energy factorization. Cross sections for longitudinally and transversally polarized mesons are…
We present a new study on helicity amplitudes and cross sections for the exclusive production of $\rho$ mesons at the EIC in high-energy factorization. In this framework the analytic expression of amplitudes takes the form of a convolution…
The operation of HERA with polarized proton and electron beams will allow to study a wide variety of observables in polarized electron-proton collisions at $\sqrt s=300$ GeV. The physics prospects of this project have been elaborated in…
We study photoproduction of jets and single-inclusive hadrons in a polarized ep collider mode of HERA at sqrt(s)=300 GeV, examining the sensitivity of the cross sections and their asymmetries to the proton's polarized gluon distribution and…
The production of $J/\psi$-pairs as a possible measure of the polarized gluon distribution $\Delta G(x)$ is studied for proton--nucleon collisions at $\sqrt{s} =40\;\mbox{GeV}^2$ (HERA-$\vec{{\rm N}}$). Possibilities of reconstructing the…
We study various conceivable photoproduction reactions in a polarized ep collider mode of HERA with respect to their sensitivity to the proton's polarized gluon distribution. A special emphasis is put on the `resolved' part of the cross…
The current uncertainty on the gluon density extracted from the global parton analysis is large in the kinematical range of small values of the Bjorken - $x$ variable and low values of the hard scale $Q^2$. An alternative to reduces this…
We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA, including statistical errors, and discuss systematic uncertainties. We…
Exclusive emissions of vector mesons in forward directions of rapidity offer us a faultless chance to probe the proton structure at small-$x$. A high-energy factorization formula is established within BFKL, given as the convolution of an…
Little information is known about the polarization of gluons inside a longitudinally polarized proton. I report on the sensitivity of photoproduction experiments to it. Both jet and heavy quark production are considered.
We describe the hard leptoproduction of transversally polarized rho-meson, up to twist 3 accuracy, including 2- and 3- particles Fock-states, in the HERA kinematics of high center-of-mass energy. We first build a model based on a simple…
We study photoproduction reactions in a polarized ep collider mode of HERA at sqrt(s)=298 GeV. We examine the sensitivity of the cross sections and their asymmetries to the proton's polarized gluon distribution and to the completely unknown…
The physics of polarized nucleon--nucleon collisions originating from an internal polarized target in the HERA proton beam is investigated. Based on 240 pb^-1 integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are given…
Results of our next-to-leading order analytic calculation for longitudinally polarized photoproduction of heavy quarks are presented. Certain differential cross sections and the corresponding asymmetries are computed for energy ranges…
The helicity structure of the diffractive electroproduction of rho mesons, e + p -> e + rho + Y, is studied in a previously unexplored region of large four-momentum transfer squared at the proton vertex, t: 0 < t' < 3 GeV^2, where t' = |t|…
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 present a systematic study of the proton spin structure in terms of measurable parton distributions. For a transversely-polarizedproton, we derive a polarization sum rule from the leading generalized parton distributions appearing in…