Exclusive photoproduction of charmonia in γp→Vp\gamma p \to V p and pp→pVpp p \to p V p reactions within ktk_t-factorization approach

The amplitude for $\gamma p \to J/\psi p$ ($\gamma p \to \psi' p$) is calculated in a pQCD $k_{T}$-factorization approach. The total cross section for this process is calculated for different unintegrated gluon distributions and compared with the HERA data and the data extracted recently by the LHCb collaboration. The amplitude for $\gamma p \to J/\psi p$ ($\gamma p \to \psi' p$) is used to predict the cross section for exclusive photoproduction of $J/\psi$ ($\psi'$) meson in proton-proton collisions. Compared to earlier calculations we include both Dirac and Pauli electromagnetic form factors. The effect of Pauli form factor is quantified. Absorption effects are taken into account and their role is discussed in detail. Different differential distributions e.g. in $J/\psi$ ($\psi'$) rapidity and transverse momentum are presented and compared with existing experimental data. The UGDF with nonlinear effects built in better describe recent experimental data of the LHCb collaboration but no definite conclusion on onset of saturation can be drawn. We present our results also for the Tevatron. A good agreement with the CDF experimental data points at the midrapidity for both $J/\psi$ and $\psi'$ is achieved.Comment: 15 pages, 19 figure

Photoproduction of J/ψJ/\psi and Υ\Upsilon states in exclusive and proton-dissociative diffractive events

The amplitude for $\gamma p \to V p$, where $V$ is a $J/\psi$ or $\Upsilon$ ground state or excited vector meson, is calculated in a pQCD $k_{T}$-factorization approach. We use this amplitude to predict the cross section for exclusive photoproduction of $J/\psi, \psi', \Upsilon$ mesons in proton-proton collisions. Calculations are performed for a variety of unintegrated gluon distributions, and we compare our results to LHCb data. Here we especially focus on the possibilty of constraining saturation effects. Compared to earlier calculations we include both Dirac and Pauli electromagnetic form factors. We discuss the role of the $Q\bar Q$ light-cone wave functions for differential distributions for ratios such as $\sigma(\psi')/\sigma(J/\psi)$. Absorption effects are always taken into account. We also discuss the related diffractive production in proton dissociative events. Here we concentrate on electromagnetic dissociation , which is calculable without additional free parameters. Besides being of interest in their own right, dissociative events constitute an important experimental background to exclusive production.Comment: 6 pages, 5 figures, Talk given by WS at the XXIV International Workshop on Deep-Inelastic Scattering and Related Subjects, 11-15 April, 2016, DESY Hamburg, German

Spatial Correlation of the Topological Charge in Pure SU(3) Gauge Theory and in QCD

We study the spatial correlator of the topological charge density operator in pure SU(3) gauge theory and in two flavor QCD. We show that the data for distances up to about 1 fm is consistent with a vacuum consisting of individual instantons and closely bound pairs. The percentage of paired objects is twice as large on the dynamical configurations than on the pure gauge ones, implying increased molecule formations due to fermionic interactions.Comment: 9 pages, 4 figure

The German grammar from its learners' perspective : learner beliefs and strategies

The purpose of this article is to analyze the results of a survey carried out with students of German as a foreign language, who were inserted in three different learning contexts in the city of São Paulo. The research aimed to investigate the beliefs of these learners concerning their process of learning the German language. The data, collected through questionnaires and interviews, revealed many of these beliefs, some related to, for example, the process of learning the German grammar. The results suggest a relationship between the beliefs and the choice of certain learning strategies. In the analysis stage, we sought to identify possible sources for the detected beliefs, as well as their potential effects on the learning process. In this article, some of the beliefs identified in the survey will be described and analyzed in relation to theoretical and methodological assumptions for teaching grammar in the didactic methods of foreign languages.O objetivo deste trabalho é divulgar e analisar os resultados de uma pesquisa realizada em três instituições paulistanas nas quais se ensina/aprende alemão como língua estrangeira. A pesquisa teve como objetivo geral investigar as crenças que alunos de língua alemã mantêm em relação a seu processo de aprendizagem. O corpus, coletado a partir de questionários e entrevistas, revelou muitas dessas crenças, referentes, por exemplo, à aprendizagem de gramática. Os resultados também apontam para a existência de uma relação entre as crenças e a adoção de determinadas estratégias de aprendizagem. Durante a análise, buscou-se identificar possíveis origens para as crenças detectadas, bem como os efeitos potenciais das mesmas sobre a aprendizagem da língua alemã. No presente artigo, algumas das crenças constatadas no estudo serão descritas e analisadas em relação a pressupostos teóricos e metodológicos da didática de línguas estrangeiras para o ensino de gramática

Multidisciplinary Consideration of Potential Pathophysiologic Mechanisms of Paradoxical Erythema with Topical Brimonidine Therapy.

Rosacea is a chronic inflammatory disease with transient and non-transient redness as key characteristics. Brimonidine is a selective α2-adrenergic receptor (AR) agonist approved for persistent facial erythema of rosacea based on significant efficacy and good safety data. The majority of patients treated with brimonidine report a benefit; however, there have been sporadic reports of worsening erythema after the initial response. A group of dermatologists, receptor physiology, and neuroimmunology scientists met to explore potential mechanisms contributing to side effects as well as differences in efficacy. We propose the following could contribute to erythema after application: (1) local inflammation and perivascular inflammatory cells with abnormally functioning ARs may lead to vasodilatation; (2) abnormal saturation and cells expressing different AR subtypes with varying ligand affinity; (3) barrier dysfunction and increased skin concentrations of brimonidine with increased actions at endothelial and presynaptic receptors, resulting in increased vasodilation; and (4) genetic predisposition and receptor polymorphism(s) leading to different smooth muscle responses. Approximately 80% of patients treated with brimonidine experience a significant improvement without erythema worsening as an adverse event. Attention to optimizing skin barrier function, setting patient expectations, and strategies to minimize potential problems may possibly reduce further the number of patients who experience side effects.FundingGalderma International S.A.S., Paris, France

Instanton Content of the SU(3) Vacuum

We study the topological content of the SU(3) vacuum using the renormalization group (RG) mapping method. RG mapping is a simple smoothing algorithm, in which a series of APE-smearing steps are done while the topological content of the configuration is carefully monitored. This monitoring process makes it possible to separate true topological objects from vacuum fluctuations and allows an extrapolation to zero smearing steps. Using RG mapping we have measured the instanton distribution and topological susceptibility for SU(3) gauge theory. We arrive at a value for the topological susceptibily, ${\chi}^{1/4}$ of 203(5) MeV. The size distribution peaks at $\rho=0.3$fm, and is in good agreement with the prediction of instanton liquid models.Comment: 12 pages, 4 figure

First results in QCD with 2+1 light flavors using the fixed-point action

This is a progress report on 2+1 flavor simulation with the FP action on a lattice with spatial size L=1.2fm. Since m_{ud} is quite small in our simulation we are in the delta regime for the two light flavors where the low lying excitations are described by a quantum mechanical rotator. From here we extract the low energy constant F. We also measure the AWI mass and present results on numerical issues like low-mode averaging and autocorrelation times.Comment: 7 pages, 6 figures, parallel talk at LATTICE 200