The Bose--Einstein (or HBT) correlation functions are evaluated for the fractal structure of QCD jets. These correlation functions have a stretched exponential (or Lévy-stable) form. The anomalous dimension of QCD determines the Lévy index of stability, thus the running coupling constant of QCD becomes measurable with the help of two-particle Bose--Einstein correlation functions. These considerations are tested on NA22 and UA1 two-pion correlation data.

PACS numbers: 05.40.Fb, 13.85.Hd, 13.87.Ce, 25.75.--q