(〈n〉/nbins) i

The behaviour of like-charge and unlike-charge second factorial moments in e + e − reactions is discussed. It is argued that Monte Carlo calculation with the help of generators JETSET 7.4 and HERWIG 5.8 points to the conclusion that the only nontrivial cause of intermittency are Bose-Einstein correlations of identical particles. Since the original proposal of Bialas and Peschanski [1], factorial moments (as well as more general quantities of the same character [2]) have become a widely accepted tool in studying multiparticle final states in various processes. Let us define the i-th factorial moment as F i = 1 N events events n bins k=1 {n k (n k − 1) · · · (n k − i + 1)} /n bins (n/n bins) i (1) where n is the average number of particles in the full phase space region accepted, b bins denotes the number of bins in this region, which is given by (2 b) d , b = 0, 1, 2... (d is the dimension of the phase space region considered) and n k is the multiplicity in k-th bin. In what follows I will consider factorial moments in two and three phase-space dimensions, in the conventional variables (y, ϕ) and (y, ϕ, ˜ p t) (y denotes rapidity, taken here from the interval (−3.2, 3.2), ϕ is the azimuthal angle and˜p t is the " flattened " momentum transverse defined as [3] ˜ p t = pt 0 P (p)dp p max t 0 P (p)dp (2)