At low x a transition from a dilute parton gas to a dense parton liquid takes place. We derive geometrical scaling for the structure function in deep inelastic scattering at low x from a diverging correlation length \xi (x) of Wilson lines near the light cone. QCD (SU(3)) in 2+1 space-time dimensions near the light cone becomes a critical theory in the limit of x  \rightarrow 0} with a diverging correlation length \xi (x) \propto x^{-{1/2 \lambda ₂}} where the exponent \lambda ₂=2.52 is obtained from the center group Z(3) of SU(3).

PACS numbers: 12.38.Lg