Analysis of flow effects in relativistic heavy-ion collisions within the CBUU approach

We study flow phenomena in relativistic heavy-ion collisions, both in transverse and radial direction, in comparison to experimental data. The collective dynamics of the nucleus-nucleus collision is described within a transport model of the coupled channel BUU type (CBUU). This recently developed version includes all nucleonic resonances up to 1.95 GeV in mass and mean-field potentials both of the Skyrme and momentum dependent MDYI type. We find that heavy resonances play an important role in the description of transverse flow above 1 AGeV incident energy. For radial flow we analyse reaction times and equilibration and extract the parameters $T$ and $\beta$ for temperature and collective flow velocity within different prescriptions. Furthermore, we apply a coalescence model for fragment production and check the mass dependence of the flow signals.Comment: 25 pages, 17 figures, submitted to Europ. Phys. J.

O perfil sociolinguístico de pais, docentes e alunos da escola Dr. Theodureto Carlos de Farias Souto, de Dionísio Cerqueira/SC

IX Congresso Brasileiro de Hispanistas realizado nos dias 22 a 25 agosto 2016Esse trabalho tem como finalidade apresentar os resultados de uma pesquisa sociolinguística realizada com professores, pais e alunos do ensino fundamental 1 (primeiro e segundo ciclos), da Escola de Educação Básica Dr. Theodureto Faria Souto, localizada no município brasileiro de Dionísio Cerqueira/SC que faz fronteira com a Argentina. A referida instituição de ensino participa, desde 2005, do Programa Escolas Interculturais de Fronteira (PEIF). Verificaramse, por meio de entrevistas, as experiências de contato com a língua espanhola, com o portunhol e com a alternância de código entre o português e o espanhol, bem como o uso dessas formas linguísticas pelos sujeitos pesquisados. Os dados da pesquisa permitem concluir que é usual e frequente a interação entre brasileiros e argentinos na fronteira de Bernardo Irigoyen e Dionísio Cerqueira. Tais situações de contato demandam conhecimentos linguísticos acerca da língua espanhola e portuguesa por brasileiros e argentinos, respectivamente. Isso reforça a pertinência de um programa como o PEIF para garantir a aquisição da língua espanhola como L2, de modo que seu ensinoaprendizagem ocorra de maneira a promover o respeito à diversidade linguística e cultural da fronteira, bem como reforçar a prática do bilinguismo comum nessas localidadesUNILA­-UNIOEST

Antiproton production in pp,dppp, dp and dddd collisions close to threshold

The production of antiprotons in $pp$ collisions is investigated close to threshold where experimental data about the total cross section are not available. We analyze the latter reaction within the LUND string model for inclusive $\bar{p}$ production and within the framework of a one-boson exchange model for the exclusive reaction $pp \rightarrow ppp\bar{p}$. The application of our new results to the analysis of subthreshold antiproton production in $d + p$ and $d + d$ collisions shows cross sections that are much lower than expected before. Nevertheless, the comparison of experimental $\bar{p}$ differential cross sections from $d +p$ and $d + d$ is expected to provide valuable information about a nonnucleonic component in the deuteron wavefunction.Comment: 10 pages, LaTeX, plus 4 postscript figures, Phys. Lett. B, in pres

On the power and size properties of cointegration tests in the light of high-frequency stylized facts

This paper first establishes a selection of stylized facts for high-frequency cointegration processes in the European equity market. Empirical evidence is given by one minute-binned transaction data of all DAX 30 constituents as traded on Deutsche Börse's Xetra market in 2014. A methodology is introduced to simulate cointegrated stock pairs, following none, some or all of the discussed stylized facts. In particular, AR(1), AR(1)-GARCH(1,1) and multiple regime STAR(1)-GARCH(1,1) processes are used to model the cointegration relationship. Furthermore, this cointegration relationship is contaminated with jumps. Based on these processes, the power and size properties of ten contemporary cointegration tests are assessed. We provide an economic interpretation of our approach by relating cointegration to relative-value arbitrage strategies in near-efficient markets. Quintessentially, we find that in a high-frequency setting typical for stock price data, selected cointegration tests still exhibit high power. Especially the Phillips-Perron and the Pantula, Gonzalez-Farias and Fuller tests perform best at very limited size distortions

Photoabsorption on nuclei

We calculate the total photoabsorption cross section on nuclei in the energy range from 300 MeV to 1 GeV within the framework of a semi-classical phase space model. Besides medium modifications like Fermi motion and Pauli blocking we focus on the collision broadening of the involved resonances. The resonance contributions to the elementary cross section are fixed by fits to partial wave amplitudes of pion photoproduction. The cross sections for $N \, R \to N \, N$, needed for the calculation of collision broadening, are obtained by detailed balance from a fit to $N \, N \to N \, N \, \pi$ cross sections. We show that a reasonable collision broadening is not able to explain the experimentally observed disappearance of the $D_{13}(1520)$-resonance in the photoabsorption cross section on nuclei.Comment: 26 pages Latex including 9 postscript figure

Components of intraday volatility and their prediction at different sampling frequencies with application to DAX and BUND futures

The adjusted measure of realized volatility suggested in [20] is applied to high- frequency orderbook and transaction data of DAX and BUND futures from EU- REX in order to identify the drivers of intraday volatility. Four components are identified to have predictive power: an auto-regressive pattern, a seasonal pattern, long-term memory and scheduled data releases. These components are analyzed in detail. Some evidence for two additional components, market microstrucuture events and unscheduled news, is given. Depending on the sampling frequency we estimate that between one and two thirds of the variation in realized volatility can be predicted by a simple linear model based on the components identified. It is shown how the predictive power of the different components depends on sampling frequencies

Analysis of Kaon Production at SIS Energies

We analyse the production and propagation of pions and kaons in heavy-ion reactions from 0.8 -- 1.8~A$\cdot$GeV within a coupled channel transport approach including the kaon production channels $BB \to K^+YN, \pi B\to K^+Y, BB \to NN K \bar{K}, \pi B\to N K\bar{K}, K^+B\to K^+B$ and $\pi \pi\to K \bar{K}$. Assuming the hyperon selfenergy to be 2/3 of the nucleon selfenergy we find that all inclusive experimental $K^+$ spectra at SIS energies can be reproduced reasonably well without any selfenergies for the kaons although a slightly repulsive kaon potential cannot be excluded by the present data on kaon spectra and flow.Comment: 19 pages, LaTeX, including 8 postscript figures, to appear in Nucl. Phys.