相关论文: Diffractive production of charm and gluon nuclear …
We calculate the cross section for q(\bar q)g-production in diffractive DIS with finite fermion masses and zero momentum transfer. The calculation is done in the leading log(1/x_p) approximation and is valid for the region of high…
The relation between diffraction in lepton-proton collisions and shadowing of nuclear structure functions which arises from Gribov inelastic shadowing, is described. A model realizing such relation, which produces a parameter-free…
We study $b\bar{b}$ and $c\bar{c}$ production and the influence of nuclear shadowing at LHC and RHIC energies. We find a significant reduction in the production cross section of both charm and bottom at RHIC and LHC. Bound states such as…
Electrons from semileptonic decays of heavy-flavor mesons (D and B) allow to study the energy loss of heavy-quarks in nuclear collisions at sqrt(s) = 200 GeV at RHIC. Since pQCD calculations have shown that the crossing point where bottom…
We generalize the leading twist theory of nuclear shadowing and calculate quark and gluon generalized parton distributions (GPDs) of spinless nuclei. We predict very large nuclear shadowing for nuclear GPDs. In the limit of the purely…
We present theoretical and experimental considerations pertaining to deeply inelastic heavy-flavour production at HERA. The various theoretical uncertainties in the cross section calculation are discussed. Cuts are imposed to determine the…
We argue that current data on nuclear shadowing confirm expectations of the color singlet models of nuclear shadowing. We demonstrate that unitarity constrains require nuclear shadowing for gluons to be very significant already for $x \le…
We discuss diffractive dissociation of gluons into heavy quark pairs. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks. The amplitude for the $g p \to Q \bar Q p$ is derived in the impact…
Nuclear shadowing and color glass condensate are possible only at sufficiently small x where parton clouds of different nucleons overlap in the longitudinal direction. Another condition vital for these effect, an overlap of partons in…
Heavy quarks, such as charm and beauty, possess masses significantly larger than the characteristic energy scale of Quantum Chromodynamics (QCD), and are thus predominantly produced in hard-scattering processes with large momentum transfer…
Measurements of $D^{*}(2010)$ meson production in diffractive deep inelastic scattering $(5<Q^{2}<100~{\rm GeV}^{2})$ are presented which are based on HERA data recorded at a centre-of-mass energy $\sqrt{s} = 319{\rm~GeV}$ with an…
In the rest frame of the nucleus, shadowing is due to hadronic fluctuations of the incoming virtual photon, which interact with the nucleons. We expand these fluctuations in a basis of eigenstates of interaction and take only the $q\bar q$…
We calculate shadowing using new data on the gluon density of the Pomeron recently measured with high precision at HERA. The calculations are made in a Glauber-Gribov framework and Pomeron tree-diagrams are summed up within 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…
The dilepton spectra from open charm decay in $p+A$ reactions at $\sqrt s=200$ AGeV are proposed to constrain gluon shadowing in nuclei. We show that the required measurements are feasible at RHIC.
In this paper, we have investigated the importance of quark charm in nuclear structure functions in the color dipole model at small $x$. The charm structure function per nucleon $F_{2}^{cA}/A$ for light and heavy nuclei in a wide range of…
We study coherent and incoherent diffractive hadron production in high energy quarkonium--heavy nucleus collisions as a probe of the gluon saturation regime of QCD. Taking this process as a model for pA collisions, we argue that the…
It is usually assumed -- following the parton model -- that the leading-twist structure functions measured in deep inelastic lepton-proton scattering are simply the probability distributions for finding quarks and gluons in the target…
We formulate the perturbative QCD approach to coherent diffractive dijet production in pion-nucleon and pion-nucleus collisions at high energy. For hard dijets the Pomeron splitting mechanism in which both helicity amplitudes are…
Nuclear shadowing corrections to the structure functions of deep inelastic scattering on intermediate-mass nuclei are calculated at very small values of Bjorken x and small values of Q^2 (Q^2<5 Gev^2). The two-component approach developed…