Correlations between neutral and charged pions in multiparticle production

We make a theoretical and phenomenological study of correlations between neutral and charged pions in multiparticle production in the framework of the so-called σ, π, ? and ?-? models. Following the method of Drijard and Pokorski, we express the predictions of various models in terms of the negative multiplicity distribution, which is known experimentally. In particular we compute the average number of $\text{π}{}^0\text{,}\text{n}{}_0\text{(n\_)}$, and the integral of π⁰?π⁰ correlations, f₀²(n_), as a function of the number of negative pions; we study also the total multiplicity distribution P(N) and its first two moments $\text{N}\text{and}\text{D}{}_{\mathrm{<mtext>tot</mtext>}}{}^2$. We show that with the present experimental accuracy neither $\text{n}{}_0\text{(n\_)}$ allow us to discriminate between the different models.