1,370 research outputs found
Diffractive production at small in future Electron - Ion Colliders
The future Electron - Ion () Collider is expected to probe the high
energy regime of the QCD dynamics, with the exclusive vector meson production
cross section being one of the most promising observables. In this paper we
complement previous studies of exclusive processes presenting a comprehensive
analysis of diffractive production at small . We compute the coherent
and incoherent cross sections taking into account non-linear QCD dynamical
effects and considering different models for the dipole - proton scattering
amplitude and for the vector meson wave function. The dependence of these cross
sections with the energy, photon virtuality, nuclear mass number and squared
momentum transfer is analysed in detail. Moreover, we compare the non-linear
predictions with those obtained in the linear regime. Finally, we also estimate
the exclusive photon, and production and compare with the
results obtained for production. Our results demonstrate that the
analysis of diffractive production in future electron - ion colliders
will be important to understand the non-linear QCD dynamics.Comment: 12 pages, 8 figures, 1 table. Enlarged and revised version to be
published in the Journal of Physics G. arXiv admin note: text overlap with
arXiv:1503.0064
Exclusive processes with a leading neutron in collisions
In this paper we extend the color dipole formalism to the study of exclusive
processes associated with a leading neutron in collisions at high
energies. The exclusive , and production, as well as the
Deeply Virtual Compton Scattering, are analysed assuming a diffractive
interaction between the color dipole and the pion emitted by the incident
proton. We compare our predictions with the HERA data on production and
estimate the magnitude of the absorption corrections. We show that the color
dipole formalism is able to describe the current data. Finally, we present our
estimate for the exclusive cross sections which can be studied at HERA and in
future electron-proton colliders.Comment: 11 pages, 9 figures. Version published in Physical Review
Investigating the impact of the gluon saturation effects on the momentum transfer distributions for the exclusive vector meson photoproduction in hadronic collisions
The exclusive vector meson production cross section is one of the most
promising observables to probe the high energy regime of the QCD dynamics. In
particular, the squared momentum transfer () distributions are an important
source of information about the spatial distribution of the gluons in the
hadron and about fluctuations of the color fields. In this paper we complement
previous studies on exclusive vector meson photoproduction in hadronic
collisions presenting a comprehensive analysis of the - spectrum measured
in exclusive , and photoproduction in and
collisions at the LHC. We compute the differential cross sections taking into
account gluon saturation effects and compare the predictions with those
obtained in the linear regime of the QCD dynamics. Our results show that gluon
saturation suppresses the magnitude of the cross sections and shifts the
position of the dips towards smaller values of .Comment: 7 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1612.0625
Exclusive vector meson production with a leading neutron in photon - hadron interactions at hadronic colliders
In this paper we study leading neutron production in photon - hadron
interactions which take place in and collisions at large impact
parameters. Using a model that describes the recent leading neutron data at
HERA, we consider exclusive vector meson production in association with a
leading neutron in collisions at RHIC and LHC energies. The total cross
sections and rapidity distributions of , and produced
together with a leading neutron are computed. Our results indicate that the
study of these processes is feasible and that it can be used to improve the
understanding of leading neutron processes and of exclusive vector meson
production.Comment: 8 pages, 3 figures, 2 table
Gluon saturation and Feynman scaling in leading neutron production
In this paper we extend the color dipole formalism to the study of leading
neutron production in collisions at high energies
and estimate the related observables, which were measured at HERA and may be
analysed in future electron-proton () colliders. In particular, we
calculate the Feynman distribution of leading neutrons, which is
expressed in terms of the pion flux and the photon-pion total cross section. In
the color dipole formalism, the photon-pion cross section is described in terms
of the dipole-pion scattering amplitude, which contains information about the
QCD dynamics at high energies and gluon saturation effects. We consider
different models for the scattering amplitude, which have been used to describe
the inclusive and diffractive HERA data. Moreover, the model dependence of
our predictions with the description of the pion flux is analysed in detail. We
show that the recently released H1 leading neutron spectra can be reproduced
using the color dipole formalism and that these spectra could help us to
observe more clearly gluon saturation effects in future colliders.Comment: 10 pages, 5 figure
Coulomb corrections to inclusive cross sections at the future Electron - Ion Collider
The experimental results of the future electron -- ion () collider are
expected to constrain the dynamics of the strong interactions at small values
of the Bjorken -- variable and large nuclei. Recently it has been suggested
that Coulomb corrections can be important in inclusive and diffractive
interactions. In this paper we present a detailed investigation of the impact
of the Coulomb corrections to some of the observables that will be measured in
the future collider. In particular, we estimate the magnitude of these
corrections for the charm and longitudinal cross sections in inclusive and
diffractive interactions. Our results demonstrate that the Coulomb corrections
for these observables are negligible, which implies that they can be used to
probe the QCD dynamics.Comment: 9 pages, 6 figures. Improved version to be published in Physical
Review
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