Related papers: Gluon- vs. Sea quark-Shadowing
We use the meson cloud model to calculate $\bar{d}(x) - \bar{u}(x)$ and $ \bar{d}(x)/\bar{u}(x)$ in the proton. We show that a modification of the symmetric, perturbative part of the light quark sea provides better agreement with the ratio…
Due to the extreme large magnetic field produced in the initial stage of non-central heavy-ion collision, the dynamical process of gluon decay into heavy quark pair will take place under an external field rather than in vacuum. Unlike in…
We study the sea quark contributions to the electromagnetic form factors of $\Sigma$ baryons with nonlocal chiral effective theory. Both octet and decuplet intermediate states are included in the one loop calculation. $G_{\Sigma^{-}}^{u}$…
Within the framework of light-cone quantisation we derive the complete and exact overlap representation of skewed parton distributions for unpolarised and polarised quarks and gluons. Symmetry properties and phenomenological applications…
Compact and well defined formulae for the shadow of the virtual photon interacting with a large nucleus at small $x_{Bj}$ are given in the QCD dipole picture. Two classes of contributions are considered: (a) quasi-elastic interaction of the…
The latest measurements of $F_2$ at HERA allow for a {\it combination} of gluon and sea quark distributions at small $x$ that is significantly different from those of existing parton sets. We perform a new global fit to deep-inelastic and…
The enhanced suppression of $J/\psi$ production at large $x_F$ in $pA$ collisions is studied in the framework of gluon depletion at large $x_1$. The nonperturbative process that modifies the gluon distribution as the gluons propagate in…
The strange sea of the proton is generally assumed to have quark - antiquark symmetry. However it has been known for some time that non-perturbative processes involving the meson cloud of the proton may break this symmetry. Recently this…
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…
Employing scalar QCD we study the gluon emission of heavy quarks created by the interaction with light quarks considered as dynamical scattering centers. We develop approximation formulas for the high energy limit and study when the full…
We show that the boundary between quark-dominated and hadron-dominated regions of nuclear structure may be blurred by multi-nucleon quark clusters arising from color percolation. Recent experiments supporting partial percolation in cold…
We analyze the quark mass dependence of photon gluon fusion in polarized deep inelastic scattering for both the intrinsic and extrinsic gluon distributions of the nucleon. We calculate the effective number of flavors for each of the heavy…
The spectrum of coherent gluon radiation from a quark-anti-quark pair experiencing multiple scatterings within a coloured medium is central for understanding in-medium parton cascades. Despite its foundational importance, current results…
We calculate nuclear shadowing in lepton-deuteron deep inelastic scattering, which arises from the double scattering of the virtual photon from both nucleons in the deuteron. The total correction to the deuteron structure function is found…
The phenomenon of shadowing of nuclear structure functions at small values of Bjorken-$x$ is analyzed. First, multiple scattering is discussed as the underlying physical mechanism. In this context three different but related approaches are…
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.
A model for the description of photonuclear reactions in the multi-GeV range is described that combines the coherent initial state interactions (shadowing) of the incoming photon with an incoherent coupled channel description of final state…
The density of states and energy spectrum of the gluon radiation are calculated for the color current of an expanding hydrodynamic skyrmion in the quark gluon plasma with a semiclassical method. Results are compared with those in…
The Chiral Quark-Soliton model provides the quark and antiquark substructure of the nucleon, which is embedded in nuclear matter. This provides a new way to asses the effects of the nuclear medium on the nucleon. We calculate nuclear…
The proton spin problem triggered by the EMC experiment and its present status are closely examined. Recent experimental and theoretical progresses and their implications are reviewed. It is pointed out that the sign of the sea-quark…