  Identical particle correlations at fixed multiplicity are consideres in the
presence of chaotic and coherent fields. The multiplicity distribution,
one-particle momentum density, and two-particle correlation function are
obtained based on the diagrammatic representation for cmulants in
semi-inclusive events. Our formulation is applied to the analysis of the
experimental data on the multiplicity dependence of correlation functions
reported by the UA1 and the OPAL Collaborations.
