Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-18T12:14:57Z No. of bitstreams: 1 arquivototal.pdf: 2895129 bytes, checksum: 572a06d99b50bb3cd9314e80d1c5b3c7 (MD5) / Made available in DSpace on 2017-09-18T12:14:57Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2895129 bytes, checksum: 572a06d99b50bb3cd9314e80d1c5b3c7 (MD5) Previous issue date: 2017-07-27 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / In this dissertation, we study the possibility of violation of the Lorentz invariance taking into account some terms of the standard extended model, more specifically, the part of this model that deals with the extended quantum electrodynamics. We perform quantum corrections in the fermionic sector of the usual quantum electrodynamics added with terms that violate the Lorentz symmetries and in two different configurations. First, the coefficient added and that causes the Lorentz symmetry breaking is introduced th­rough the constant pseudo-tensor Ic juvAp And we treat the constant electric and magnetic fields, that is, we do not evaluate as external leg between the coupling of the photon and fermions, evaluating the field FAp Without opening in term of the gauge field. In the second case, we investigated the operators governed by the coefficient of interaction FAp open in term of the gauge field. In the second case, we investigated the mixed contribu­tion of the minimum and non-minimum coupling. We immediately know that for each coupling evaluated will have their respective vertices. For both cases, we calculate the quantum corrections in a loop. In the first case, the theory with the coefficient Ic juvAp and field FAp without being opened at the end of the gauge field AP, The contribution of a loop and we calculate the counter-ter, having a CPT-par characteristic, which will be useful to be introduced in action to eliminate divergences. In the second case, we examined the contribution of a loop, considering the mixture of minimum and non-minimum coupling, that is, and and and an external one AP, having a CPT-par characteristic, One related to the non-minimum coupling and another to the minimum, respectively and verifying the vertex correction also having the contribution of its counter-term. / Nesta dissertagao, estudamos a possibilidade de violagao da invariancia de Lorentz le­vando em conta alguns termos do modelo padrao estendido, mais especificamente da parte do modelo que trata da eletrodinamica quantica estendida. Realizamos corregoes quanticas no setor fermiOnico da eletrodinamica quantica usual adicionada de termos que violam as simetrias de Lorentz e em duas configuragoes diferentes. Primeiramente, o co­eficiente adicionado e que ocasiona a quebra de simetria de Lorentz é introduzida atraves do pseudo-tensor constante is juvAp e tratamos os campos eletricos e magneticos constantes, ou seja, nao avaliamos como perna externas entre o acoplamento do fOton e fermions, avaliando o campo FAp sem abrir em termo do campo de gauge. No segundo caso, investi­gamos a contribuigao mista do acoplamento minim° e nao-minimo. De imediato sabemos que para cada acoplamento avaliado tera seus respectivo vertices. Para os dois casos, cal­culamos as corregoes quanticas em um lago. No primeiro caso, a teoria com o coeficiente I c juvAp e campo FAp sem ser aberto em termo do campo de gauge AP, a contribuigao de um lago e calculamos a pega de polo, tendo uma caracteristica CPT-par, que sera iltil para ser introduzida na agao para eliminar as divergencias. No segundo caso, nos examinamos a contribuigao de um lago, considerando a mistura dos acoplamento minimo e nao-minimo, ou seja, um Fill, e um externo AP, tendo como caracteristica CPT-impar um relacionado ao acoplamento nao-minimo e outro ao minimo, respectivamente e verificando a corregao de vertice tendo tambem a contribuigao do seu contra termo.