On the origin of approximate KNO scaling ine ⁺ e ⁻ annihilation

Abstract

KNO scaling of the multiplicity distribution in hadronic final states was originally derived as a consequence of Feynman scaling. We show that in iterative models of hadron production in jets, incorporating Feynman scaling, KNO scaling obtains only in the limit when the width of the multiplicity distribution tends to zero. Within the context of the models currently employed to describee ⁺ e ⁻ annihilation into hadrons, the apparent KNO scaling observed is an accidental consequence of effects which violate Feynman scaling.