REALISTIC EXPANDING SOURCE MODEL FOR INVARIANT ONE-PARTICLE MULTIPLICITY DISTRIBUTIONS AND 2-PARTICLE CORRELATIONS IN RELATIVISTIC HEAVY-ION COLLISIONS

We present a realistic expanding source model with nine parameters tha t are necessary and sufficient to describe the main physics occurring during hydrodynamical freeze-out of the excited hadronic matter produc ed in relativistic heavy-ion collisions. As a first test of the model, we compare it to data from central Si + Au collisions at p(lab)/A=14. 6 GeV/c measured in experiment E-802 at the Brookhaven Alternating Gra dient Synchrotron. An overall chi(2) per degree of freedom of 1.055 is achieved for a fit to 1416 data points involving invariant pi(+), pi( -), K+, and K- one-particle multiplicity distributions and pi(+) and K + two-particle correlations. The 99%-confidence region of parameter sp ace is identified, leading to one-dimensional error estimates on the n ine fitted parameters and other calculated physical quantities. Three of the most important results are the freeze-out temperature, longitud inal proper time, and baryon density along the symmetry axis. For thes e we find values of 92.9 +/- 4.4 MeV, 8.2 +/- 2.2 fm/c, and 0.0222(-0. 0069)(+0.0096) fm(-3), respectively.