Independent Emission of Neutral and Charged Clusters In High-Energy Hadron Collisions

A general formalism for the simultaneous emission of neutral and charge clusters is considered. For application, we study in detail a typical two-component model based on cluster emissions. We parameterize the diffractive component by a $\pi \sigma$ scheme and the nondiffractive component by a $\pi B$ scheme. In the nondiffractive component, the strength parameters for the emission of both $\pi$ and $B$ are found empirically to be linear in $\ln p_{\mathrm{Lab}}$ in reminiscence of the expectation of a multiperipheral model. Furthermore, the direct pion emission is found to dominate in the low-energy region (20-30 GeV/c), while beyond 100 GeV/c, the $B$ emission becomes more important. This indicates that the clustering effect becomes more and more important as the energy increases. The charge multiplicity distribution and the average ${\pi }^0$ multiplicity at fixed ${\pi }^{-}$ number ${〈n_0〉}_{-}$ vs $n_{-}$, predicted by the model are in good agreement with the data. Asymptotically the separation of the two components becomes noticeable at around 1000-1500 GeV/c and the prediction for ${〈n_0〉}_{-}$ vs $n_{-}$ at 1500 GeV/c is essentially the same as that at 205 GeV/c. Most features enumerated here appear to be quite general properties of two-component models involving the direct independent emission of pions and other clusters, insensitive to the specific $\pi B$ scheme assumed.