Model independent analysis of nearly L\'evy correlations

A model-independent method for the analysis of the two-particle short-range correlations is presented, that can be utilized to describe e.g. Bose-Einstein (HBT), dynamical (ridge) or other correlation functions, that have a nearly L'evy or streched exponential shape. For the special case of L'evy exponent alpha = 1, the earlier Laguerre expansions are recovered, for the alpha = 2 special case, a new expansion method is obtained for nearly Gaussian correlation functions. Multi-dimensional L'evy expansions are also introduced and their potential application to analyze rigde correlation data is discussed.