FLUCTUATIONS AND HBT SCALES IN ULTRARELATIVISTIC HEAVY-ION COLLISIONS

Bose-Einstein correlations in relativistic heavy ion collisions are ex amined in a general model containing some of the essential features of hydrodynamical, cascade as well as other models commonly employed for describing the particle freeze-out. The HBT radii are expressed in te rms of fluctuations of quantities due to longitudinal and transverse e xpansion, emission from surfaces moving in time, the thickness of the emitting layer varying from surface to volume emission and other effec ts. Model dependencies of freeze-out sizes and times are discussed and compared to recent preliminary Pb + Pb data at 160 A . GeV. (C) 1998 Elsevier Science B.V.