“…In the direction of this struck quark the scaled momentum spectra of the particles, expressed in terms of x p = 2p Breit /Q, are expected to have a dependence on Q similar to that observed in e + e − annihilation [2,3,4] at energy √ s = Q. Within the modified leading log approximation (MLLA) there are predictions of how the higher order moments of the parton momentum spectra should evolve with energy scale [5,6]. The parton level predictions depend on two free parameters, a running strong coupling, governed by a QCD scale Λ, and an energy cut-off, Q 0 , below which the parton evolution is truncated.…”