Search

Your search keyword '"Helayël-Neto, José A."' showing total 335 results
Start Over Author "Helayël-Neto, José A."
335 results on '"Helayël-Neto, José A."'

102. Remarks on the Static Potential Driven by Vacuum Nonlinearities in Models

Author

Gaete, Patricio and Helayël-Neto, José A.

Abstract

Within the framework of the gauge-invariant, but path-dependent, variables formalism, we study the manifestations of vacuum electromagnetic nonlinearities in D=3 models. For this we consider both generalized Born-Infeld and Pagels-Tomboulis-like electrodynamics, as well as Euler-Heisenberg-like electrodynamics. We explicitly show that generalized Born-Infeld and Pagels-Tomboulis-like electrodynamics are equivalent, where the static potential profile contains a long-range (1/r2-type) correction to the Coulomb potential. Interestingly enough, for Euler-Heisenberg-like electrodynamics the interaction energy contains a linear potential, leading to the confinement of static charges.

Published
2016

104. Aspects of Screening and Confinement in a Topologically Massive Chern-Simons-Higgs Theory

Author

Gaete, Patricio and Helayël-Neto, José A.

Subjects
Computer Science::Digital Libraries
Abstract

By using the gauge-invariant but path-dependent variables formalism, we consider a recently proposed topologically massive U1W×U(1)Y Chern-Simons-Higgs theory in 2+1 dimensions. In particular, we inspect the impact of a Chern-Simons mixing term between two Abelian gauge fields on physical observables. We pursue our investigation by analyzing the model in two different situations. In the first case, where we integrate the massive excitation and consider an effective model for the massless field, we show that the interaction energy contains a linear term leading to the confinement of static charge probes along with a screening contribution. In the second situation, where the massless field can be exactly integrated with its constraint duly taken into account, the interesting feature is that the resulting effective model describes a purely screening phase, without any trace of a confining regime.

Published
2016

105. Aspects of Screening and Confinement in a Topologically Massive U1W×U(1)Y Chern-Simons-Higgs Theory

Author

Gaete, Patricio and Helayël-Neto, José A.

Subjects
High Energy Physics::Theory, Article Subject, lcsh:Physics, lcsh:QC1-999
Abstract

By using the gauge-invariant but path-dependent variables formalism, we consider a recently proposed topologically massive U1W×U(1)Y Chern-Simons-Higgs theory in 2+1 dimensions. In particular, we inspect the impact of a Chern-Simons mixing term between two Abelian gauge fields on physical observables. We pursue our investigation by analyzing the model in two different situations. In the first case, where we integrate the massive excitation and consider an effective model for the massless field, we show that the interaction energy contains a linear term leading to the confinement of static charge probes along with a screening contribution. In the second situation, where the massless field can be exactly integrated with its constraint duly taken into account, the interesting feature is that the resulting effective model describes a purely screening phase, without any trace of a confining regime.

Published
2016

106. David Bohm’s Quantum Mechanics

Author

Siqueira-Batista, Rodrigo and Helayël-Neto, José Abdalla

Subjects
Mecânica Quântica, Hidden variables, lcsh:H1-99, Quantum Physics, Variáveis ocultas, lcsh:Social sciences (General), David Bohm, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, lcsh:Science (General), David Bohm. Quantum Mechanics. Hidden variables, Quantum Mechanics, lcsh:Q1-390
Abstract

Bohm’s interpretation of Quantum Mechanics appears as one of the main alternatives to the hegemonic model proposed by the Copenhagen School. This works aims at making a concise presentation of the outlines and the main conceptual framework of the approach followed by David Bohm. A interpretação bohmiana da Mecânica Quântica representa uma das principais alternativas ao modelo hegemônico proposto pela Escola de Copenhague. Apresentar, sucintamente, seus principais aspectos conceituais, é o objetivo do presente artigo.

Published
2010

123. Physical properties of the spin Hamiltonian on honeycomb lattice samples with Kekulé and vacuum polarization corrections.

Author

Helayël-Neto, José Abdalla, Martins, Ricardo Spagnuolo, Konstantinova, Elena, and Belich, Humberto

Subjects
*LATTICE dynamics, *HONEYCOMB structures, *KEKULE structures, *MAGNETIC susceptibility, *SPECIFIC heat, *MONTE Carlo method, *VACUUM polarization
Abstract

Magnetic and thermodynamical properties of a system of spins in a honeycomb lattice, such as magnetization, magnetic susceptibility and specific heat, in a low-temperature regime are investigated by considering the effects of a Kekulé scalar exchange and QED vacuum polarization corrections to the interparticle potential. The spin lattice calculations are carried out by means of Monte Carlo simulations. We present a number of comparative plots of all the physical quantities we have considered and a detailed analysis is presented to illustrate the main features and the variation profiles of the properties with the applied external magnetic field and temperature. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

130. An algebraic proof on the finiteness of Yang-Mills-Chern-Simons theory in D=3

Author

Del Cima, O M, Franco, D H T, Helayël-Neto, José A, and Piguet, O

Subjects
High Energy Physics::Theory, 81T13, 81T15, 81T17, 81T20, FOS: Physical sciences, Mathematical Physics (math-ph), Particle Physics - Theory, Mathematical Physics
Abstract

A rigorous algebraic proof of the full finiteness in all orders of perturbation theory is given for the Yang-Mills-Chern-Simons theory in a general three-dimensional Riemannian manifold. We show the validity of a trace identity, playing the role of a local form of the Callan-Symanzik equation, in all loop orders, which yields the vanishing of the beta-functions associated to the topological mass and gauge coupling constant as well as the anomalous dimensions of the fields., 5 pages, revtex

Published
1999

133. Simulador de Oscilações Mecânicas.

Author

da Silva, Adilson Costa and Helayël Neto, José Abdalla

Subjects
*MECHANICAL oscillations, *COMPUTER simulation, *ACCELERATION (Mechanics)
Abstract

We have recently developed a software to simulate a given physical phenomenon, without the need of knowing its corresponding equation of motion. This procedure is actually intended to illustrate the behavior of dynamical variables of interest, such as position, velocity, acceleration and energy. In our work, we present analytical solutions for each case under consideration; numerical solutions carried out by means of the finite difference method are presented as well. The harmonic oscillator is a moving periodical system, with a well-defined equilibrium position. We shall here present an overview of the general problem to be solved and a number of special cases shall be worked out in details. As one of the purposes of this article is to encourage readers to use numerical approaches to inspect physical problems, we shall discuss in a simple and direct way the numerical solutions of a mechanical oscillator. We also contemplate the behavior of the energy function and point out under which particular situations it is conserved. To validate the numerical method implemented in our paper, we compare the analytical solutions we derive with the results obtained by numerical computations. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

134. Aspects of Screening and Confinement in a Topologically Massive U1W×U(1)Y Chern-Simons-Higgs Theory.

Author

Gaete, Patricio and Helayël-Neto, José A.

Subjects
*CHERN-Simons gauge theory, *STATIC electricity, *ELECTROSTATIC interaction, *NUCLEAR excitation, *SCALAR field theory
Abstract

By using the gauge-invariant but path-dependent variables formalism, we consider a recently proposed topologically massive U1W×U(1)Y Chern-Simons-Higgs theory in 2+1 dimensions. In particular, we inspect the impact of a Chern-Simons mixing term between two Abelian gauge fields on physical observables. We pursue our investigation by analyzing the model in two different situations. In the first case, where we integrate the massive excitation and consider an effective model for the massless field, we show that the interaction energy contains a linear term leading to the confinement of static charge probes along with a screening contribution. In the second situation, where the massless field can be exactly integrated with its constraint duly taken into account, the interesting feature is that the resulting effective model describes a purely screening phase, without any trace of a confining regime. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results