Recent tests of parton hadron duality in multiparticle final states

Abstract

A large variety of jet properties can be described perturbatively by evolving the parton cascade down to small scales of order of a few 100 MeV. We discuss two recent applications of this approach: 1. the soft limit of the particle spectrum which is nearly energy independent as expected for the soft gluon bremsstrahlung; further tests of this interpretation in $e^{+}{e}^{-}$ and DIS are presented; 2. the steep decrease of the distribution of rapidity gaps in $e^{+}{e}^{-}$ annihilation can be explained by the Sudakov formfactor for quark jets.

LaTex, 13 pages, 4 figures, presented at the Ringberg workshop "New Trends in HERA Physics", Tegernsee, Germany, 25-30 May 1997