1998/09/28 by A. Ster, T. Csorgo, B. Lorstad
Physics and Astronomy · #hep-ph
published as Proc. CF'98 (WSCI 1999, ed. T. Csorgo et al) p. 137 · 10 pages, TeX, including 2 tables and 1 figure
arxiv created 1998/09/28 · arxiv updated 2009/11/30
Analytic and numerical approximations to a hydrodynamical model describing longitudinally expanding, cylindrically symmetric, finite systems are fitted to preliminary NA44 data measured in 200 AGeV central S + Pb reactions. The model describes the measured spectra and HBT radii of pions, kaons and protons, simultaneously. The source is characterized by a central freeze-out temperature of T0 = 154 +/- 8 +/- 11 MeV, a "surface" temperature of Tr = 107 +/- 28 +/- 18 MeV and by a well-developed transverse flow, <ut> = 0.53 +/- 0.17 +/- 0.11. The transverse geometrical radius and the mean freeze-out time are found to be RG = 5.4 +/- 0.9 +/- 0.7 fm and tau0 = 5.1 +/- 0.3 +/- 0.3 fm/c, respectively. Fits to preliminary WA93 200 AGeV S + Au and WA98 158 AGeV Pb + Pb data dominated by pions indicate similar model parameters. The absolute normalization of the measured particle spectra together with the experimental determination of both the statistical and the systematic errors were needed to obtain successful fits.