Two-component model for the associated multiplicity in inclusive reactions

Abstract

We present a simple, two-component model for the charged multiplicity associated with the observed particle in an inclusive reaction. At small ${p}_{T}$ the scattering is ascribed to a coherent or "soft" component, whereas at large ${p}_{T}$ the production mechanism is assumed to be incoherent or "hard." At fixed incident energy and missing mass, the ${p}_{T}$ dependence of ${\overline{n}}_{c}$ is given by the relative weights of hard and soft scattering, so that the multiplicity is a sensitive probe of the transition region between the two components. The model is applied to recent multiplicity data for $\mathrm{pp}\ensuremath{\rightarrow}\mathrm{pX}$ and $\mathrm{pp}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}X$ at 28.5 GeV/c, as well as to data at Fermilab and CERN-ISR energies.