Multiboson effects in multiparticle production - art. no. 034901

The influence of multiboson effects on pion multiplicities, single-pion spe ctra, and two-pion correlation functions is discussed in terms of an analyt ically solvable model. The applicability of its basic factorization assumpt ion is clarified. An approximate scaling of the basic observables with the phase space density is demonstrated in the low density (gas) limit. This sc aling and also its violation at high densities due to the condensate format ion is described by approximate analytical formulas which allow, in princip le, for the identification of the multiboson effects among others. For mode rate densities indicated by the experimental data, a fast saturation of mul tiboson effects with the number of contributing cumulants is obtained, allo wing for the account of these effects in realistic transport code simulatio ns. At high densities, the spectra are mainly determined by the universal c ondensate term and the initially narrow Poisson multiplicity distribution a pproaches a wide Bose-Einstein one. As a result, the intercepts of the incl usive and fixed-n correlation functions (properly normalized to 1 at large relative momenta) approach 2 and 1, respectively, and their widths logarith mically increase with the increasing phase space density. It is shown that the neglect of energy-momentum constraints in the model is justified except near a multipion threshold, where these constraints practically exclude th e possibility of a very cold condensate production. It is argued that spect acular multiboson effects are likely to be observed only in the rare events containing sufficiently high density (speckle) fluctuations.