Unitarity
Mostrando 1-12 de 23 artigos, teses e dissertações.
-
1. Unitarity in Noncommutative Field Theories / Unitariedade em teorias não comutativas
Este trabalho é dedicado ao estudo da unitariedade em teoria de campos não comuta- tiva. Inicialmente, são apresentadas as ferramentas básicas para abordar o problema da unitariedade em teorias não comutativas, incluindo as regras de corte e uma introdução à não comutatividade. Em seguida, foi feita a análise do modelo Á3 não comutativo. Empregan
Publicado em: 2009
-
2. Sinais de produção de novos bósons vetoriais no LHC / Signals of production of new vector bosons at the LHC
In this work we performed a phenomenological observation of new spin-1 bosons associated with the Electroweak Symmetry Breaking sector. As motivation for this analysis we previously studied the special case of models based on the mechanism of Eletroweak Symmetry Breaking via Boundary Conditions, which also have a tower vector of Kaluza-Klein bosons ensuring
Publicado em: 2009
-
3. Analytical, empirical and phenomenological aspects of elastic hadron scattering at high energies / Aspectos analiticos, empiricos e fenomenologicos do espalhamento elastico de hadrons em altas energias
We investigate high-energy elastic hadron scattering by means of three different approaches: analytical, empirical, and phenomenological. The first one is characterized by the fundamental principles of analyticity and crossing symmetry, polynomial limits for the scattering amplitude and dispersion relations. In special, for classes of functions of physical i
Publicado em: 2009
-
4. The role of crossing symmetry for a low energy pion-nucleon scattering from dispersive method
The slow convergence of chiral perturbation theory for heavy baryons (HBChPT) suggests that any attempt to unitarize the amplitude following from this method will fail to describe the experimental phase shifts. However, it was possible to obtain a ChPT pion nucleon amplitudes respecting exact unitarity relation by using the Inverse Amplitude Method (IAM), bu
Brazilian Journal of Physics. Publicado em: 2008-09
-
5. A Study of Soft Interactions at Ultra High Energies
We present and discuss our recent study of an eikonal two channel model, in which we reproduce the soft total, integrated elastic and diffractive cross sections, and the corresponding forward differential slopes in the ISR-Tevatron energy range. Our study is extended to provide predictions at the LHC and Cosmic Rays energies. These are utilized to assess the
Brazilian Journal of Physics. Publicado em: 2008-09
-
6. On the quantum dynamics of non-commutative systems
This is a review paper concerned with the global consistency of the quantum dynamics of non-commutative systems. Our point of departure is the theory of constrained systems, since it provides a unified description of the classical and quantum dynamics for the models under investigation. We then elaborate on recently reported results concerned with the suffic
Brazilian Journal of Physics. Publicado em: 2008-06
-
7. Diffraction in QCD
This lecture presents a short review of the main features of diffractive processes and QCD inspired models. It includes the following topics: (1) Quantum mechanics of diffraction: general properties; (2) Color dipole description of diffraction; (3) Color transparency; (4) Soft diffraction in hard reactions: DIS, Drell-Yan, Higgs production; (5) Why Pomerons
Brazilian Journal of Physics. Publicado em: 2007-07
-
8. High density QCD through eletromagnetic probes
In this work we investigate the high density QCD system through the dilepton production. First, the dilepton production in the color dipole approach is investigated, studing perturbative unitarity corrections to the dipole cross section and its consequence in the transverse momentum distribution of the dileptons at RHIC and LHC energies. Second, the dilepton
Brazilian Journal of Physics. Publicado em: 2007-07
-
9. Ressonâncias escalares: relações dinâmicas entre processos de espalhamento e decaimento / Scalar resonances: dynamic relations between scattering and decay processes
A existência de um méson escalar-isoescalar leve, conhecido como ?, foi proposta pela primeira vez na década de 60. A partícula tinha então um papel importante na construção teórica das interações ?? mas, apesar dos esforços experimentais, ela não foi detectada nos anos que se seguiram. Essa situação foi radicalmente alterada em 2001, quando um
Publicado em: 2007
-
10. Saturation in high-energy QCD
In these proceedings, I shall review the basic concepts of perturbative QCD in its high-energy limit, emphasising the approach to the unitarity limit, usually referred to as saturation. I shall explain the basic framework showing the need for saturation, first, from a simple picture of the high-energy behaviour, then, giving a short derivation of the equatio
Brazilian Journal of Physics. Publicado em: 2006-12
-
11. Remarks on the dynamical mass generation in confining Yang-Mills theories
The dynamical mass generation for gluons is discussed in Euclidean Yang-Mills theories supplemented with a renormalizable mass term. The mass parameter is not free, being determined in a self-consistent way through a gap equation which obeys the renormalization group. The example of the Landau gauge is worked out explicitly at one loop order. A few remarks o
Brazilian Journal of Physics. Publicado em: 2006-03
-
12. The extended ADS/CFT correspondence
The correspondence between conformal covariant fields in Minkowski's space-time and isometric fields in the five dimensional anti-deSitter space-time is extended to a six-dimensional bulk space and its regular sub-manifolds, so as to include the analysis of evaporating Schwarzschild's black holes without loss of quantum unitarity.
Brazilian Journal of Physics. Publicado em: 2005-12