It is argued that the scaling property of higher dimensional normalized factorial moments depends essentially on the different ways of phase space division. The later can be characterized by the log ratio of partition number in different directions of phase space. Two examples are given. Firstly, a self-affine analysis of factorial moments was carried out on the NA22 data for pi(+)p and K(+)p collisions at 250 GeV/c. It turns out that the Hurst exponent is only one half when the longitudinal direction is compared to the transverse ones, providing a first experimental evidence on the anisotropy...
