Correlations Between Neutral and Charged Pions in Multiparticle Production

We investigate the dynamical significance of correlations between ${〈n_0〉}_{-}$ and $n_{-}$, where ${〈n_0〉}_{-}$ is the mean number of neutral pions observed in conjunction with $n_{-}$ negative tracks in high-energy multiparticle production processes. Several models are treated in turn. Pions are assumed to be produced either singly or in clusters, according to a Poisson or inverse-power distribution. Influences of charge, isospin, and energy-momentum conservation are studied. The linear rise of ${〈n_0〉}_{-}$ vs $n_{-}$ observed experimentally at very high energies is shown to rule out some models of multiperipheral type, but is in accord with fragmentation models and with a multiperipheral model in which $\rho$- or $\omega$-type meson clusters are emitted.