No abstract

We analyse second moments R 2 of like-sign pion pairs in the two-dimensional (q L , q T ) and three-dimensional (q O , q S , q L ) decompositions of the three-momentum difference. Conventional fit parametrisations such as gaussian, exponential, power-law and Edgeworth fail miserably, while more elaborate ones such as Lévy do well but fail to yield a unique best-fit solution. A twocomponent model using a hard cut to separate small-and large-scale parts appears possible but not compelling. In all cases, the data exhibits a strong and hitherto unexplained peak at small momentum differences which exceeds current fits.