6,818 research outputs found
Spin-1 Particles with Light-Front Approach
For the vector sector, i.e, mesons with spin-1, the electromagnetic form
factors and anothers observables are calculated with the light-front approach.
However, the light-front quantum field theory have some problems, for example,
the rotational symmetry breaking. We solve that problem added the zero modes
contribuition to the matrix elements of the electromagnetic current, besides
the valence contribuition. We found that among the four independent matrix
elements of the plus component in the light-front helicity basis only the one carries zero mode contributions.Comment: 5 pages. 3 Figures, use latex and EPJ styl
The Electromagnetic Form Factor of the Kaon in the Light-Front Approach
The kaon electromagnetic form factor is calculated within a light-front
constituent quark model (LFCQM). The electromagnetic components of the current
are extracted from the Feynman triangle diagram within the light-front
approach. We also obtain the electroweak decay constant and the charge radius
for the kaon in the light-front approach. In this work, the kaon observables
are calculated and a fairly good agreement is obtained with a very higher
accuracy when compared with the experimental data.Comment: Paper with 4 pages, 1 figure, reference: XII HADRON PHYSICS
Conference - to appear in AIP Conference Proceeding
Electromagnetic Structure of the Pion
In this work, we analyze the electromagnetic structure of the pion. We
calculate its electromagnetic radius and electromagnetic form factor in low and
intermediate momentum range. Such observables are determined by means of a
theoretical model that takes into account the constituent quark and antiquark
of the pion within the formalism of light-front field theory. In particular, we
consider a nonsymmetrical vertex in this model, with which we calculate the
electromagnetic form factor of the pion in an optimized way, so that we obtain
a value closer to the experimental charge radius of the pion. The theoretical
calculations are also compared with the most recent experimental data involving
the pion electromagnetic form factor and the results show very good agreement.Comment: Paper with 4 pages, 1 figure, presented in XII HADRON PHYSICS
Conference - to appear in AIP Conference Proceeding
The organizational and social impact of emerging technologies: The case of blockchains
The results of a questionnaire that seeks to ascertain the organizational and social impact of the blockchain technology in Portugal are presented. It is structured according to the model proposed by the authors, which presents the following 3 parts: characterization of the respondents' profile, factors of knowledge and of use of the blockchain technology, and expectations and impact of this technology in Portugal. The main results indicate a still very low penetration in our country, as well as pressing needs for dissemination, investment, education and training on this technology. The relevance of the results presented in this chapter is related to the importance of arousing interest, dissemination about the expected impact and measures to enhance the positive impact of this technology.info:eu-repo/semantics/acceptedVersio
Primeiro registro de Diphaulaca sp. na cultura da mamona no Estado do PiauĂ, Brasil.
bitstream/item/83269/1/CT1930001.pd
- …