Hanbury-Brown/Twiss Interferometry for Relativistic Heavy-Ion   Collisions: Theoretical Aspects
  I discuss two-particle intensity interferometry as a method to extract from measured 1- and 2-particle momentum spectra information on the space-time geometry and dynamics of the particle emitting source. Particular attention is given to the rapid expansion and short lifetime of the sources created in relativistic heavy-ion collisions. Model-independent expressions for the HBT size parameters in terms of the space-time variances of the source are derived, and a new parametrization of the correlation function is suggested which allows to separate the transverse, longitudinal and temporal extension of the source and to measure its transverse and longitudinal expansion velocity. The effects of resonance decays are also discussed. 
Ulrich Heinz