32,130 research outputs found
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
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
Inelastic quarkonium photoproduction in coherent hadron - hadron interactions at LHC energies
In this paper we study the inelastic quarkonium photoproduction in coherent
interactions. Considering the ultra relativistic hadrons as a
source of photons, we estimate the total ( and ) cross sections and rapidity distributions at
LHC energies. Our results demonstrate that the experimental analysis of this
process can be used to understand the underlying mechanism governing heavy
quarkonium production.Comment: 9 pages, 7 figures, 3 table
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
Modelling the kinetics of thermal inactivation of apple polyphenoloxidase
The enzymatic browning of fruits and vegetables caused by mechanical injury during postharvest storage or processing is initiated by the catalytic action of polyphenoloxidase (PPO). A bleaching
treatment prior to processing is still considered mostly effective in inhibiting the catalytic activity of PPO,
and thus controlling undesirable enzymatic browning. In this work, different mathematical routines were
assessed in terms of their adequacy to describe the thermal inactivation of PPO from Golden apples over a
range of temperatures from 62.5 to 72.5 ÂşC. The classical approach to kinetic modelling of the decay activity
of apple PPO, commonly reported to follow a first-order model, employs a two-step procedure, in which the
model parameters are individually obtained, by each temperature studied, using non-linear or linear
regressions. Thereafter, the estimated parameters are further used to calculate their temperature dependence.
Alternatively, a one-step method provides a regression fit to all experimental data sets, with the temperature
dependence equation being directly built in the kinetic model. This fitting technique thus, (a) avoids the
estimation of intermediate parameters and, (b) substantially increases the degrees of freedom and hence the
precision of parameters’ estimates. Within this issue was further explored the logarithmic transformation of
the mathematical equations used on the adequacy of the model to describe experimental data. In all cases
non-weighted least-squares regression procedures were used. Both the examination and criticism of the
current modelling strategies were done by assessing statistical data obtained, such as the confidence intervals
of the estimates, correlation coefficients, sum of squares, and residuals normality
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