Resolving Power of 2-D Pion Interferometry

A $\chi^2$ analysis is performed to test the resolving power of two-dimensional pion interferometry using for illustration the preliminary E802 data on $Si+Au$ at 14.6 AGeV/c. We find that the resolving power to distinguish two decoupling geometries of different dynamical models is enhanced by studying the variation of the mean $\chi^2$ per degrees of freedom with respect to the range of the analysis in the $q_T,q_L$ plane. The preliminary data seem to rule out dynamical models with significant $\omega,\eta$ resonance formation yields.