9 research outputs found
Saturation in diffractive deep inelastic eA scattering
In this paper we investigate the saturation physics in diffractive deep
inelastic electron-ion scattering. We estimate the energy and nuclear
dependence of the ratio and predict the x_{\pom}
and behavior of the nuclear diffractive structure function
. Moreover, we analyze the ratio
,
which probes the nuclear dependence of the structure of the Pomeron. We show
that saturation physics predicts that approximately 37 % of the events observed
at eRHIC should be diffractive.Comment: 15 pages, 7 figures. Version to be published in the European Physical
Journal
Exclusive processes in electron - ion collisions
The exclusive processes in electron-ion () interactions are an important
tool to investigate the QCD dynamics at high energies as they are in general
driven by the gluon content of the target, which is strongly subject to parton
saturation effects. In this paper we compute the cross sections for the
exclusive vector meson production as well as the deeply virtual Compton
scattering (DVCS) relying on the color dipole approach and considering the
numerical solution of the Balitsky-Kovchegov equation including running
coupling corrections (rcBK). The production cross sections obtained with the
rcBK solution and bCGC parametrization are very similar, the former being
slightly larger.Comment: 6 pages, 4 figure
Saturation physics at HERA and RHIC: An unified description
One of the frontiers of QCD which are intensely investigated in high energy
experiments is the high energy (small ) regime, where we expect to observe
the non-linear behavior of the theory. In this regime, the growth of the parton
distribution should saturate, forming a Color Glass Condensate (CGC). In fact,
signals of parton saturation have already been observed both in deep
inelastic scattering at HERA and in deuteron-gold collisions at RHIC.
Currently, the description of the experimental data of these experiments is
possible considering different phenomenological saturation models for the two
processes within the CGC formalism. In this letter we analyze the universality
of these dipole cross section parameterizations and verify that they are not
able to describe the HERA and RHIC data simultaneously. We analyze possible
improvements in the parameterizations and propose a new parametrization for the
forward dipole amplitude which allows us to describe quite well the small-
HERA data on structure function as well as the RHIC data on
charged hadron spectra. It is an important signature of the universality of the
saturation physics.Comment: 12 pages, 4 figures. Version to be published in Physics Letters
Probing the Color Glass Condensate in an electron-ion collider
Perturbative Quantum Chromodynamics (pQCD) predicts that the small- gluons
in a hadron wavefunction should form a Color Glass Condensate (CGC),
characterized by a saturation scale which is energy and atomic
number dependent. In this paper we study the predictions of CGC physics for
electron - ion collisions at high energies. We consider that the nucleus at
high energies acts as an amplifier of the physics of high parton densities and
estimate the nuclear structure function , as well as the
longitudinal and charm contributions, using a generalization for nuclear
targets of the Iancu-Itakura-Munier model which describes the HERA data
quite well. Moreover, we investigate the behavior of the logarithmic slopes of
the total and longitudinal structure functions in the kinematical region of the
future electron - ion collider eRHIC.Comment: 18 pages, 9 figures. Version to be published in the European Physical
Journal
Nuclear shadowing in Glauber-Gribov theory with Q2-evolution
We consider deep inelastic scattering off nuclei in the Regge limit within
the Glauber-Gribov model. Using unitarized parton distribution functions for
the proton, we find sizeable shadowing effects on the nuclear total and
longitudinal structure functions, and , in the low-x limit.
Extending a fan-diagram analysis for the large-mass region of coherent
diffraction off nuclei to high Q2, we also find significant shadowing effects
in this kinematical regime. Finally, we discuss shortcomings of our approach
and possible extensions of the model to other kinematical regimes.Comment: 16 pages, 9 figure