Common origin of the shoulder in multiplicity distributions and of   oscillations in the factorial cumulants to factorial moments ratio
  The shoulder structure of charged particles multiplicity distributions (MD's) in full phase space in $e^+e^-$ annihilation at the $Z_0$ peak and the quasi-oscillatory behavior of the ratio of factorial cumulants over factorial moments, $H_q$, as a function of the order $q$, are quantitatively reproduced within a simple parametrization of the MD in terms of a weighted superposition of two Negative Binomial Distributions, associated to two- and multi-jet production, i.e., to hard gluons radiation. 
Alberto Giovannini (Turin U. & INFN, Turin), Sergio Lupia (Munich, Max   Planck Inst.), Roberto Ugoccioni (Lund U.)