16,601 research outputs found
Investigating the exclusive protoproduction of dileptons at high energies
Using the high energy color dipole approach, we study the exclusive
photoproduction of lepton pairs. We use simple models for the elementary
dipole-hadron scattering amplitude that captures main features of the
dependence on atomic number A, on energy and on momentum transfer t. This
investigation is complementary to conventional partonic description of timelike
Compton scattering, which considers quark handbag diagrams at leading order in
and simple models of the relevant generalized parton distributions
(GPDs). These calculations are input in electromagnetic interactions in pp and
AA collisions to measured at the LHC.Comment: 6 pages, 4 figure
Exclusive photoproduction of J/psi and psi(2S) states in pp and AA collisions at the LHC
In this contribution we report on the investigations of the exclusive
production of J/psi and psi(2S) states in proton-proton and nucleus-nucleus
reactions at the LHC using the theoretical framework of light-cone dipole
formalism.Comment: Presented at EDS Blois 2013 (arXiv:1309.5705
Investigating the central diffractive f0(980) and f2(1270) meson production at the LHC
The central diffractive production of mesons f0(980) and f2(1270) at the
energy of CERN-LHC experiment on proton-proton collisions is investigated. The
processes initiated by quasi-real photon-photon collisions and by central
diffraction processes are considered. The role played by the photon-Odderon
production channel is also studied. The cross sections for these distinct
production channels are compared and analyzed.Comment: 7 pages, 4 tables. Final version to be published in Physical Review
D. arXiv admin note: text overlap with arXiv:hep-ph/0508196,
arXiv:hep-ph/0506101 by other author
Exclusive photoproduction of dileptons at high energies
The exclusive photoproduction of lepton pairs on nucleon and nucleus target
is investigated within the high energy color dipole approach, where the main
physical quantity is the dipole-target elastic scattering amplitude that
captures the main features of the dependence on atomic number A, on energy and
on momentum transfer t. These calculations are input in predictions for
electromagnetic interactions in pp and AA collisions to be measured at the LHC.Comment: 5 pages, 1 figure and 1 table. Contribution to the proceedings of
XXXVIII International Symposium on Multiparticle Dynamics (ISMD2008).
Hamburg, Germany, 15-20 September 200
Investigating diffractive W production in hadron-hadron collisions at high energies
We compute the hard diffractive hadroproduction of bosons W at high energies
using Regge factorization and taking into account multiple Pomeron exchange
corrections. The ratio of diffractive to non-diffractive W production agrees
with the current Tevatron data and a prediction for the LHC is presented.Comment: 4 pages, 1 table. To appear in the proceedings of 10th International
Workshop on Hadron Physics (X Hadron Physics), Florianopolis, Brazil, 26-31
Mar 200
Neutrino structure functions in the QCD dipole picture
In this contribution we present an exploratory QCD analysis of the neutrino
structure functions in charged current DIS using the color dipole formalism.
The corresponding dipole cross sections are taken from recent phenomenological
and theoretical studies in deep inelastic inclusive production, including
nuclear shadowing corrections. The theoretical predictions are compared to the
available experimental results in the small-x region.Comment: 4 pages, 2 figures. To appear in the proceedings of the XXXVI
International Symposium on Multiparticle Dynamics. September 02-08, 2006
Paraty, Rio de Janeiro, Brazi
Chaos and dynamical trends in barred galaxies: bridging the gap between N-body simulations and time-dependent analytical models
Self-consistent N-body simulations are efficient tools to study galactic
dynamics. However, using them to study individual trajectories (or ensembles)
in detail can be challenging. Such orbital studies are important to shed light
on global phase space properties, which are the underlying cause of observed
structures. The potentials needed to describe self-consistent models are
time-dependent. Here, we aim to investigate dynamical properties
(regular/chaotic motion) of a non-autonomous galactic system, whose
time-dependent potential adequately mimics certain realistic trends arising
from N-body barred galaxy simulations. We construct a fully time-dependent
analytical potential, modeling the gravitational potentials of disc, bar and
dark matter halo, whose time-dependent parameters are derived from a
simulation. We study the dynamical stability of its reduced time-independent
2-degrees of freedom model, charting the different islands of stability
associated with certain orbital morphologies and detecting the chaotic and
regular regions. In the full 3-degrees of freedom time-dependent case, we show
representative trajectories experiencing typical dynamical behaviours, i.e.,
interplay between regular and chaotic motion for different epochs. Finally, we
study its underlying global dynamical transitions, estimating fractions of
(un)stable motion of an ensemble of initial conditions taken from the
simulation. For such an ensemble, the fraction of regular motion increases with
time.Comment: 17 pages, 11 figures (revised version, accepted for publication in
Mon. Not. R. Astron. Soc.
- …