Study of the doubly charmed tetraquark T+cc

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed

Environment, safety and regulation: abstracts, posters and lectures.

The objectives of this workshop were: to facilitate the exchange of information and ideas regarding harmonized approaches available for the scientific evaluation and regulation of crop protection chemistry; to provide a forum for presentation of the latest research in the areas of agricultural biotechnology, environmental and human health protection, risk management and regulation of crop protection chemicals in Latin America. With this effort research and regulatory scientists, working in the area of crop protection chemistry and biotechnology, will gain new insights regarding trends and emerging developments in agricultural science

L’Anti-Macunaíma: l’industriale brasiliano Delmiro Gouveia attraverso la narrativa di Mário de Andrade

The purpose of this essay is to analyze the figure of Delmiro Gouveia, Brazilian industrialist, as a counterpart of Macunaíma in Mário de Andrade’s scriptures. Chronicles, letters and Macunaíma’s romance will be the sources for this research. Differently from the character in Andrade’s novel, in which Delmiro Gouveia is represented as a lazy worker, we will observe in these documents that this man was a unique Brazilian, dedicated to the progress of his own country

Recognising Complex Prepositions Prep+N+Prep as

This work is a study of the delimitation of complex prepositions (CP) as lexical units, items of a computational lexicon that includes compounds and phrases

On the treatment of acoustical problems with the hybrid boundary element method

The symmetric hybrid boundary element method in the frequency and time domain is introduced for the computation of acoustic radiation and scattering in closed and infinite domains. The Hybrid Stress Boundary Element Method (HSBEM) in a frequency domain formulation is based on the dynamical Hellinger-Reissner potential and leads to a Hermitian, frequency-dependent sitffness equation. On the other hand, the Hybrid Displacement Boundary Element Method (HDBEM) for time domain starts out from Hamilton's principle formulated with the velocity potential. The field variables in both formulations are separated into boundary variables, which are approximated by piecewise polynomial functions, and domain variables, which are approximated by a superposition of singular fundamental solutions, generated by Dirac distributions, and generalized loads, that are time dependent in the transient case. The domain is modified, such that small spheres centered at the nodes are subtracted. Then the property of the Dirac distribution, now acting outside the domain, cancels the remaining domain integral in the hybrid principle and leads to a boundary integral formulation, incorporating singular integrals. In the time domain formulation, an analytical transformation is employed to transform the remaining domain integral into a boundary one. This approach results in a linear system of equations with a symmetric dynamic stiffness matrix. Examples for exterior radiation problems and a 3D example for transient wave propagation in a closed domain are presented. (orig.)Available from TIB Hannover: RR 6943(99-11) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

La Seconda guerra mondiale sugli schermi: un’analisi sul cinema nel Nordeste

This paper analyzes the relationship between the cinemas located in the city of Aracaju (located in Brazil’s Northeast) and the movies shown at the time of World War II. The cinemas’ scheduling varied according to changes in U.S. movie production, and it also depended on the international position of Brazil, considering the War and the countries involved in the conflict. Newspapers and magazines constitute the bulk of the documentation that supports an analysis of the films exhibition at a time when the mass media were controlled with political purposes