Aspectos da função beta da teoria de Yang-Mills supersimétrica

• Ano de defesa: 2012
• Autor(a) principal: Helvecio Geovani Fargnoli Filho
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Física; Teoria quântica de campos; Renormalizacao
• Link de acesso: http://hdl.handle.net/1843/MPDZ-8Y3GRJ

Since the pioneering works there exists a controversy about the origin of the radiative contribuituions to the supersymmetric Yang-Mills beta function. In supersymmetric theories the chiral anomaly and the trace anomaly are related. While the former is exact in one loop order due to the Adler-Bardeen theorem the latter is proportional to the beta function and explicit calculations of find higher order contributions. This conflict is known as anomaly puzzle. In this work we calculate the pure N = 1supersymmetric Yang-Mills beta function up to two loops using Implicit Regularization. Despite the two-loop ultraviolet divergent piece being null we find a nonzero second order beta function coefficient through the renormalization group equation. We shed light on the infrared divergences role consistently separating them from the ultraviolet ones. According with our calculation, off-shell infrared divergences have no role obtaining the beta function - as one could expect. However on-shell infrared divergences are important.