  A particular initial state for the construction of a perturbative QCD
expansion is investigated. It is formed as a coherent superposition of zero
momentum gluon pairs and shows Lorentz as well as global $SU(3)$ symmetries.
The general form of the Wick theorem is discussed, and it follows that the
gluon and ghost propagators determined by the proposed vacuum state, coincides
with the ones used in an alternative of the usual perturbation theory proposed
in a previous work, and reviewed here. Therefore, the ability of such a
procedure of producing a finite gluon condensation parameter already in the
first orders of perturbation theory is naturally explained. It also follows
that this state satisfies the physicality condition of the BRST procedure in
its Kugo and Ojima formulation. A brief review of the canonical quantization
for gauge fields, developed by Kugo and Ojima, is done and the value of the
gauge parameter $\alpha$ is fixed to $\alpha=1$ where the procedure is greatly
simplified. Therefore, after assuming that the adiabatic connection of the
interaction does not take out the state from the interacting physical space,
the predictions of the perturbation expansion for the physical quantities, at
the value $\alpha=1$, should have meaning. The validity of this conclusion
solves the gauge dependence indeterminacy remained in the proposed perturbation
expansion.
