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.