QCD coherence and the soft limit of the particle spectrum

Abstract Perturbative QCD predicts an energy independent limit for the density of partons at small momenta in a jet which follows from the colour coherence in soft gluon production. The existing data on the charged and identified particle inclusive spectra in e + e − annihilation follow closely the perturbative prediction for partons which is in support of the local parton hadron duality picture also for low momentum particles. Further tests of this interpretation of the data are proposed.