31,312 research outputs found

    Investigating diffractive W production in hadron-hadron collisions at high energies

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    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

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    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

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    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 αs\alpha_s 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

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    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

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    In this paper we study the inelastic quarkonium photoproduction in coherent pp/pPb/PbPbpp/pPb/PbPb interactions. Considering the ultra relativistic hadrons as a source of photons, we estimate the total h1+h2→h⊗V+X h_1 + h_2 \rightarrow h \otimes V + X (V=J/ΨV = J/\Psi and Υ\Upsilon) 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

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    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

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    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 ºC. 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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