Fluctuation-induced higher-derivative couplings and infrared dynamics of the quark-meson-diquark model

Abstract

In a qualitative study, the low-energy properties of the $\text{SO}\!\left(6\right)$-symmetric Quark-Meson-Diquark Model as an effective model for two-color Quantum Chromodynamics are investigated within the Functional Renormalization Group (FRG) approach. In particular, we compute the infrared scaling behavior of fluctuation-induced higher-derivative couplings of the linear Quark-Meson-Diquark Model and map the resulting renormalized effective action onto its nonlinear counterpart. The higher-derivative couplings of the nonlinear model, which we identify as the low-energy couplings of the Quark-Meson-Diquark Model, are therefore entirely determined by the FRG flow of their linear equivalents. This grants full access to their scaling behavior and provides insights into conceptual aspects of purely bosonic effective models, as they are treated within the FRG. In this way, the presented work is understood as an immediate extension of our recent advances in the $\text{SO}\!\left(4\right)$-symmetric Quark-Meson Model beyond common FRG approximations.