Potenciais entre quarks e antiquarks em modelos não perturbativos

• Autor(a) principal: Correa, Carlos Stivens Mena
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/12886
• topic: Quantum Chromodynamics; Confinement and Effective Models for QCD; Quantum Field Theory; Non Relativistic Potentials; Cromodinâmica Quântica; Confinamento e Modelos Efetivos para QCD; Teoria Quântica de Campos; Potenciais não Relativísticos; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DAS PARTICULAS ELEMENTARES E CAMPOS

In this Master thesis, we investigated some non-perturbative models for Quantum Chromodynamics (QCD) with the purpose of testing its validity in the perturbative region of nuclear interaction and to explore its behavior in the infrared region. In particular, we focused on the calculations and analysis of the potentials between supermassive quarks and antiquarks, since this observable might reveal the appearance of confinement properties in non-perturbative models through a linear growth at large and intermediate distances. We calculated the potentials associated with the massive Gluon, Gribov-Zwanziger and Refined Gribov-Zwanziger models at tree level for the non-relativistic case, comparing them to: (i) the perturbative case, given its successful experimental test at high energies, and (ii) the results of Lattice QCD simulations, which is not limited to the low coupling regime and can reproduce observables such as the hadron masses. To calculate the potentials, we gave a brief description of the Functional Formalism of Quantum Field Theory in order to write the Functional Generator of QCD and thus obtain Feynman s rules of theory, which allowed us to calculate the functions of our interest. In addition, we have included the flux of the Renormalization Group in the QCD coupling constant, which allowed us to study the energy-scale dependence of the parameters of the potentials treated here. Our results indicate that, in the tree-level approximation, all potentials we have obtained can reproduce the perturbative result at high energies and some of them bring significant non-perturbative corrections. Due to these results we can consider that the systematic inclusion of more interaction effects may lead to improvements in the quark-antiquark potential description, and an initial analysis of the one-loop corrections has also been included in this Master thesis.