  We study the Landau gauge correlators of Yang-Mills fields for infrared
Euclidean momenta in the context of a massive extension of the Faddeev-Popov
Lagrangian which, we argue, underlies a variety of continuum approaches.
Standard (perturbative) renormalization group techniques with a specific,
infrared-safe renormalization scheme produce so-called decoupling and scaling
solutions for the ghost and gluon propagators, which correspond to nontrivial
infrared fixed points. The decoupling fixed point is infrared stable and weakly
coupled, while the scaling fixed point is unstable and generically strongly
coupled except for low dimensions $d\to2$. Under the assumption that such a
scaling fixed point exists beyond one-loop order, we find that the
corresponding ghost and gluon scaling exponents are, respectively,
$2\alpha_F=2-d$ and $2\alpha_G=d$ at all orders of perturbation theory in the
present renormalization scheme. We discuss the relation between the ghost wave
function renormalization, the gluon screening mass, the scale of spectral
positivity violation, and the gluon mass parameter. We also show that this
scaling solution does not realize the standard Becchi-Rouet-Stora-Tyutin
symmetry of the Faddeev-Popov Lagrangian. Finally, we discuss our findings in
relation to the results of nonperturbative continuum methods.
