IR fixed point and low-momentum gluon propagator

Abstract

Assuming the gluon propagator to be finite at $ g^{2}_{s} /4\pi \equiv \alpha \rightarrow \alpha_{\ast} $, where $ \alpha_{\ast} = \alpha (0) $, we derive its low-momentum asymptotics. In some cases the results modify the known ones. In our work, we also establish the field-theoretical nature of a universal phenomenological parameter introduced in works \cite{Alk} and determining the behaviour of Green's functions in the infrared region. The importance of studying the renormalization group parameters in the vicinity of the infrared stable point is emphasized.