Bose-Einstein correlations for three-dimensionally expanding, cylindrically symmetric, finite systems.

There are two type of scales present simultaneously in the space-like as well as in the time-like directions in a model-class describing a cylindrically symmetric, finite, three-dimensionally expanding boson source. One type of the scales is related to the finite lifetime or geometrical size of the system, the other type is governed by the rate of change of the local momentum distribution in the considered temporal or spatial direction. The parameters of the Bose-Einstein correlation function may obey an Mt-scaling, as observed in S + Pb and Pb + Pb reactions at CERN SPS. This Mt-scaling may imply that the Bose-Einstein correlation functions view only a small part of a big and expanding system. The full sizes of the expanding system at the last interaction are shown to be measurable with the help the invariant momentum distribution of the emitted particles. A vanishing duration parameter can also be generated, with a specific Mt dependence, in the considered model-class. ∗ [email protected], [email protected] 1