A new class of Hanbury-Brown/Twiss parameters
  In heavy ion collisions resonances can create strong non-Gaussian effects in the 2-pion correlation data. Hence, the commonly used Gaussian fit parameters do not fully characterize these correlators. We suggest a different set of HBT parameters which does not presuppose a particular shape of the correlator and allows to extract additional (non-Gaussian) information. Within a simple model for an expanding source including resonance decays it is shown that this additional information provides a clean distinction between scenarios with and without transverse flow. 
Urs Achim Wiedemann, Ulrich Heinz