Dimensional Regularization and Chiral Theories

  • Jan. 13, 2022, 2:30 pm US/Central
  • Marija Mador-Bozinovic, University of Zagreb

Dimensional Regularization is one of the most commonly employed schemes for practical calculations in perturbative quantum field theories. High precision tests in particle accelerators require theoretical constraints which in principle need complicated multiloop calculations, accessible in the framework of Dimensional Regularization. In this scheme, however, the γ5 Dirac matrix needs to remain purely 4-dimensional in order to be able to describe theories with chiral anomalies, which are necessary due to the fact that the existence of chiral fermions is a fundamental fact of nature. It is possible either to introduce inconsistencies or to keep the mathematical rigor with Breitenlohner – Maison -`t-Hooft – Veltman scheme, with the consequence of breaking gauge and BRST symmetry. However, it is possible to restore symmetries with a choice of proper local counterterms, which are evaluated using the Quantum Action Principle, which will be demonstrated in this seminar talk.