Effects of fermions in one-loop propagators in the Curci-Ferrari-Delbourgo-Jarvis gauge

Abstract

We present the one-loop computation of the quark propagator in the Curci-Ferrari-Delbourgo- Jarvis (CFDJ) gauge, extending previous analyses to include dynamical quarks. Using the infrared- safe renormalization scheme, we study how finite gauge parameters affect the infrared behavior of QCD correlation functions. The coupling, gluon mass, and gauge parameter are found to freeze below a finite energy scale, confirming the infrared stability of the framework. The quark dressing function Z(p) shows a change in concavity between the Landau and finite-ξ cases, suggesting that nonvanishing gauges may better reproduce lattice trends. These results establish the CFDJ gauge as a possible infrared-safe setting candidate for perturbative QCD with massive gluons. In the case of a consistency check from lattice calculations, it could provide a basis for future studies of the quark-gluon vertex and related observables.

Figures (20)

• Figure 1: Diagrams contributing to the ghost self energy at one loop.
• Figure 2: Diagrams contributing to the gluon self energy at one loop.
• Figure 3: Contributions at one loop to the $h^{a}A^{b}_{\mu}$ vertex and $h^{a}$-field self energy, respectively.
• Figure 4: Diagram contributing to the quark self energy at one loop.
• Figure 5: Running of the gauge coupling $g(\mu)$, the gluon mass $m(\mu)$ and the gauge parameter $\xi(\mu)$ in the IS scheme, for $N_f=2$ degenerate quarks.