Search results for "matemática"
showing 10 items of 434 documents
Meson-meson interactions in a nonperturbative chiral approach
1999
A non-perturbative method which combines constraints from chiral symmetry breaking and coupled channel unitarity is used to describe the meson-meson interaction up to about 1.2 GeV. The approach uses the O(p^2) and O(p^4) chiral Lagrangians. The seven free parameters of the O(p^4) Lagrangian are fitted to the data. The results are in good agreement with a vast amount of experimental analyses. The amplitudes develop poles in the complex plane corresponding to the f0, a0, rho, K*, phi, sigma and kappa resonances; the latter two, very broad. The total and partial decay widths of the resonances are also well reproduced. Further extensions and applications of this chiral non-perturbative scheme …
Nonperturbative approach to effective chiral Lagrangians and meson interactions
1998
We develop a coupled channel unitary approach describing the behavior at higher energies of systems whose low-energy dynamics is given by effective O(p^2) and O(p^4) chiral Lagrangians. Our free parameters are those of the O(p^4) Lagrangian. When applied to the meson-meson interaction, it yields a remarkable agreement with data up to sqrt{s}=1.2 GeV, dynamically generating the sigma, f_0, a_0,rho and K^* resonances. Further applications are also proposed.
Comments on the dispersion relation method to vector–vector interaction
2019
We study in detail the method proposed recently to study the vector-vector interaction using the $N/D$ method and dispersion relations, which concludes that, while for $J=0$, one finds bound states, in the case of $J=2$, where the interaction is also attractive and much stronger, no bound state is found. In that work, approximations are done for $N$ and $D$ and a subtracted dispersion relation for $D$ is used, with subtractions made up to a polynomial of second degree in $s-s_\mathrm{th}$, matching the expression to $1-VG$ at threshold. We study this in detail for the $\rho - \rho$ interaction and to see the convergence of the method we make an extra subtraction matching $1-VG$ at threshold…
Nature of the axial-vector mesons from their N-c behavior within the chiral unitary approach
2008
By describing within the chiral unitary approach the g-wave interaction of the vector meson nonet with the octet of pseudoscalar Goldstone bosons, we find that the main component of the axial-vector mesons -b(1)(1235), h(1)(1170), h(1)(1380), a(1)(1260), f(1)(1285) and the two states associated to the K-1(1270)- does not follow the QCD dependence on the number of colors for ordinary q (q) over bar mesons.
Characterization of the optical properties at the ANTARES site using the Optical Beacon system. Influence on the detector performance
2014
Neutrino Astronomy aims to scientifically exploit neutrinos as a new cosmic messenger to explore high energy astrophysical phenomena in the TeV-PeV energy range. The very low fluxes and the small interaction crosssection of neutrinos with matter require the construction of massive detectors. When the incoming neutrino direction can be reconstructed with a reasonable angular accuracy, the detector is dubbed "telescope", since the neutrinos, having no electric charge, point back to their source. In the Cherenkov technique, the observation of the neutrino is carried out through the detection of the Cherenkov light induced by the charged relativistic particles produced in the neutrino interacti…
La tradición matemática griega y el dominio del mundo en el Renacimiento
2009
[EN] In this article we want to show how mathematics have been considered as a part of the tertiary education along the history. Our thesis here is both, any change in the education system must consider its character of universal language in Science and Technology and also its role as a pure science itself and the fact that mathematical teaching has been historically deve oped in the framework of the engineering education. The Mathematical Knowledge since the Ancien Age can not be easily understood without considering the context where it was generated and, in this sense, the teaching of Mathematics in Engineering Education plays a crucial role where any kind of mathematical knowledge, pure…
Varieties of special Jordan algebras of almost polynomial growth
2019
Abstract Let J be a special Jordan algebra and let c n ( J ) be its corresponding codimension sequence. The aim of this paper is to prove that in case J is finite dimensional, such a sequence is polynomially bounded if and only if the variety generated by J does not contain U J 2 , the special Jordan algebra of 2 × 2 upper triangular matrices. As an immediate consequence, we prove that U J 2 is the only finite dimensional special Jordan algebra that generates a variety of almost polynomial growth.
Analytical and numerical comparison of position based methods versus physics based formulation of mechanical systems
2017
La simulación de sistemas mecanicos para videojuegos y otras aplicaciones interactivas impone restricciones importantes como estabilidad, flexibilidad en las escenas, y complejidad computacional. En los últimos años han aparecido múltiples estrategias de resolución para sistemas mecánicos con restricciones. Algunos de los más populares en el ámbito de videojuegos únicamente usan las posiciones de las partículas y un algoritmo de proyección sobre la variedad definida por las restricciones, evitando la manipulación de la primera derivada del sistema (las velocidades), obteniendo así gran estabilidad numérica. El principal problema de estos métodos es la dependencia en parámetros no físicos, d…
Distribuciones previas objetivas para el modelo Dirichlet-multinomial: una aplicación en la agricultura
2015
La chufa, Cyperus sculentus, es un tubérculo que se utiliza principalmente para la elaboración de horchata. Se cultiva en la comarca de l'Horta Nord, en Valencia, y tiene una gran importancia socioeconómica en la zona. La mancha negra en los tubérculos de chufa es una enfermedad de origen desconocido, que produce un ennegrecimiento de la piel que conlleva a su depreciación comercial, pues un cierto porcentaje de tubérculos deben ser desechados para su venta. El objetivo de este trabajo es analizar si la selección de tubérculos sin mancha negra, para su utilización como simiente, supone una mejora en la cosecha en cuanto a una menor incidencia de la enfermedad. Los datos analizados proceden …
Análisis de la adecuación de libros de texto de E. Primaria a la enseñanza a estudiantes de altas capacidades matemáticas
2013
Un problema al que se enfrentan los profesores de matemáticas de Enseñanza Primaria es la necesidad de hacer adaptaciones en sus programaciones para ofrecer una educación adecuada a sus alumnos de altas capacidades matemáticas. Las editoriales de libros de texto de matemáticas de estos niveles educativos ofrecen diversas soluciones que, usualmente, consisten en incluir, en el libro del alumno, algunos problemas más difíciles y, en la documentación del profesor, una propuesta de problemas de ampliación. Una cuestión que se plantea al analizar un libro de texto de matemáticas es valorar cómo de útil puede ser el material proporcionado por la editorial (libro de texto y materiales complementar…