Exclusive glueball production in high energy nucleus-nucleus collisions

The cross sections for the glueball candidates production in quasi-real photon-photon collisions and on central diffraction processes, i.e. double Pomeron exchange, in heavy ion interactions at RHIC and LHC are computed. The rates for these distinct production channels are compared and they may be a fruitful approach to the investigation of glueballs.Comment: 6 pages, 2 tables. Final version to be published in Physical Review

Information entropy of classical versus explosive percolation

We study the Shannon entropy of the cluster size distribution in classical as well as explosive percolation, in order to estimate the uncertainty in the sizes of randomly chosen clusters. At the critical point the cluster size distribution is a power-law, i.e. there are clusters of all sizes, so one expects the information entropy to attain a maximum. As expected, our results show that the entropy attains a maximum at this point for classical percolation. Surprisingly, for explosive percolation the maximum entropy does not match the critical point. Moreover, we show that it is possible determine the critical point without using the conventional order parameter, just analysing the entropy's derivatives.Comment: 6 pages, 6 figure

VSR symmetries in the DKP algebra: the interplay between Dirac and Elko spinor fields

VSR symmetries are here naturally incorporated in the DKP algebra on the spin-0 and the spin-1 DKP sectors. We show that the Elko (dark) spinor fields structure plays an essential role on accomplishing this aim, unravelling hidden symmetries on the bosonic DKP fields under the action of discrete symmetries.Comment: 17 page

Meson decay in the Fock-Tani Formalism

The Fock-Tani formalism is a first principle method to obtain effective interactions from microscopic Hamiltonians. Usually this formalism was applied to scattering, here we introduced it to calculate partial decay widths for mesons.Comment: Presented at HADRON05 XI. "International Conference on Hadron Spectroscopy" Rio de Janeiro, Brazil, August 21 to 26, 200

Meson decay in a corrected 30P3^P_0 model

Extensively applied to both light and heavy meson decay and standing as one of the most successful strong decay models is the $3^P_0$ model, in which $q\bar{q}$ pair production is the dominant mechanism. The pair production can be obtained from the non-relativistic limit of a microscopic interaction Hamiltonian involving Dirac quark fields. The evaluation of the decay amplitude can be performed by a diagrammatic technique for drawing quark lines. In this paper we use an alternative approach which consists in a mapping technique, the Fock-Tani formalism, in order to obtain an effective Hamiltonian starting from same microscopic interaction. An additional effect is manifest in this formalism associated to the extended nature of mesons: bound-state corrections. A corrected $3^P_0$ is obtained and applied, as an example, to $b_{1}\to\omega\pi$ and $a_{1}\to\rho\pi$ decays.Comment: 3 figures. To appear in Physical Review

Arquitetura, Filosofia e Paisagem

The discussion on architectural, environmental and urban quality within the disciplinary area of architecture is often based on several aspects, such as the suitability of the architectural work to the place, the context, the landscape, that is, to the physical space that surrounds it. This question is not only raised in physical terms (considering form, climate, topography, access, views, etc.), but also in aesthetic and symbolic terms. In the disciplinary area of architecture, it is frequent to refer to the physical characteristics (natural or built) leaving a little aside the issues arising from the action of man as interpreter of the landscape. The purpose of our approach is to increase the type of readings advanced in the field of architecture essentially centered on the shape of buildings and their relationship to the landscape based on descriptive data. In this way, from the contributions of the architecture and philosophy areas, the architectural places and the landscape are viewed from two different points of view: as objects considered abstractly in relation to the context in which they are produced and interpreted and as works resulting from human action, that is, produced by someone who is inserted in a given cultural community and placed in a particular historical situation.info:eu-repo/semantics/publishedVersio