Abstract:
There are two length-scales present simultaneously in all the principal directions for three-dimensionally expanding, finite systems. These are discussed in detail for the case of a longitudinally expanding system with a transverse flow and a transverse temperature profile. For systems with large geometrical sizes we find an mtm_t-scaling for the parameters of the Bose-Einstein correlation function, which may be valid in the whole transverse mass region for certain model parameters. In this limit, the Bose-Einstein correlations view only a small part of the source. The large geometrical sizes can be inferred from a simultaneous analysis of the invariant momentum distribution and the Bose-Einstein correlation function. A preliminary analysis of the NA44 data indicates that instead of a small fireball we are observing a big and expanding snowball in S+PbS + Pb reactions at CERN SPS energies.
Note:
  • 5 pages, no figures, ReVTeX, uses espcrc1.sty, Quark Matter'95 conference, Nucl. Phys. A in press Report-no: CU-TP-684, LUNFD6/(NFFL-7106) 1995
  • talk: Monterey 1995/01/09
  • scattering: heavy ion
  • heavy ion: scattering
  • nucleus nucleus: nuclear reaction
  • sulfur
  • lead
  • multiple production
  • boson: statistics
  • correlation function
  • momentum spectrum