Angular Moment Analysis of Correlations
  For analyzing anisotropic low relative-velocity correlation-functions and the associated emission sources, we propose an expansion in terms of cartesian spherical harmonics. The expansion coefficients represent angular moments of the investigated functions. The respective coefficients for the correlation and source are directly related to each other via one-dimensional integral transforms. The shape features of the source may be partly read off from the respective features of the correlation function and can be, otherwise, imaged. 
P. Danielewicz and S. Pratt (Michigan State U)