  Multi-boson symmetrization effects on two-particle Bose-Einstein
interferometry are studied for ensembles with arbitrary multiplicity
distributions. This generalizes the previously studied case of a Poissonian
input multiplicity distribution. In the general case we find interesting
residual correlations which require a modified framework for extracting
information on the source geometry from two-particle correlation measurements.
In sources with high phase-space densities, multi-boson effects modify the
Hanbury Brown-Twiss (HBT) radius parameters and simultaneously generate strong
residual correlations. We clarify their effect on the correlation strength
(intercept parameter) and thus explain a variety of previously reported
puzzling multi-boson symmetrization phenomena. Using a class of analytically
solvable Gaussian source models, with and without space-momentum correlations,
we present a comprehensive overview of multi-boson symmetrization effects on
particle interferometry. For event ensembles of (approximately) fixed
multiplicity, the residual correlations lead to a minimum in the correlation
function at non-zero relative momentum, which can be practically exploited to
search, in a model-independent way, for multi-boson symmetrization effects in
high-energy heavy-ion experiments.
