You are here
Nonperturbative analysis of seagull divergences in QCD
David Ibanez Gil de Ramales
Quantum field theories with ɸ4-like interactions contain seagull-type graphs, which in turn generate quadratic divergences at the level of the two-point function, that must be properly renormalized through appropriate counterterms of the the type m20(Ʌ2UV)ɸ2. In the case of nonperturbative QCD with a dynamical gluon mass generation mechanism, quadratic divergences occur at the level of the Schwinger-Dyson equation satisfied by the gluon propagator. However, since gauge invariance for bids the appearance of such counterterms involving the gluon field, one is forced to adopt different regularization/renormalization procedures for dealing with these divergences. In this seminar I will present a method to get rid of the aforementioned seagull divergences in nonperturbative QCD; it relies on the ability of triggering an identity called “seagull identity”, valid in dimensional regularization.